Skip to main content
sudhanshu_sabharwal
Sudhanshu Sabharwal
November 25, 2025
Solved

test

  • November 25, 2025
  • 6 replies
  • 32 views

test

    Best answer by sudhanshu_sabharwal

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    6 replies

    Inspiring
    November 26, 2025

    hello

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 18, 2025

    origin L2 - 1

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 18, 2025

    origin L3 - 1

     

     

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 9, 2025

    hi

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 9, 2025

    Hello again

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 18, 2025

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    rule InvisiDoor_Backdoor : backdoor windows
    {
        meta:
            description = "Identifies the InvisiDoor stealth backdoor malware."
            author = "AI Security Bot"
            date = "2025-11-06"
            version = "1.0"
            severity = "High"

        strings:
            // Text string often used in the malware's command-and-control communication
            $c2_ip = "192.168.42.10" fullword ascii

            // Unique mutex name the malware creates to ensure only one instance runs
            $mutex = "InvisiDoor_Global_Mutex_01" wide ascii

            // A specific sequence of binary instructions (hex pattern) in the code
            // '??' represents a wildcard (any single byte)
            $code_pattern = { 55 8B EC 83 E4 F8 FF 75 ?? 6A 00 }

            // A regular expression to find an obfuscated configuration file path
            $config_resgex = /%APPDATA%\\Roaming\\[a-z]{4}\.dat/ nocase

        condition:
            // The file must contain the unique mutex string ($mutex)
            // AND it must contain either the C2 IP ($c2_ip) OR the code pattern ($code_pattern)
            // AND the file size must be between 10 KB and 500 KB
            $mutex and ($c2_ip or $code_pattern) and filesize > 10KB and filesize < 500KB
    }

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 18, 2025

    origin L3 - 2

     

     

    sudhanshu_sabharwal
    Sudhanshu Sabharwal
    December 18, 2025

    answer