Backdoor:W32/SdBot.AAY spreads by exploiting a variety of vulnerabilities and can be controlled by a remote attacker through a password-protected IRC channel.
The backdoor's file is a PE executable about 210 kilobytes long, packed with SVPK file compressor.
When the backdoor's file is started, it copies itself as 'mssvces.exe' file to Windows System folder and then creates the following startup key value in the Registry:
- "Shell" = "Explorer.exe mssvces.exe"
The bot exploits the following vulnerabilities in order to spread:
- LSASS (MS04-011) port 445
- WKSSVC (MS03-049) port 445
- ASN.1 (MS04-007) ports 80, 139, 445
When the backdoor is active, it connects to an IRC server, joins a certain channel and acts as a bot there. The backdoor also starts IDENTD server on port 113.
The following IRC server and ports are used by the backdoor: