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 }