Windows 2003/XP/2000/NT/ME/98/95

Gaobot.PFN is a worm that spreads by copying itself, without infecting other files.

It captures certain information entered or saved by the user, with the corresponding threat to privacy: passwords saved by certain Windows services; keystrokes, in order to obtain information for accessing online banking services, passwords and other confidential information.

It affects productivity, preventing tasks from being carried out:

• In the affected computer: it converts the computer into a platform for taking malicious action surreptitiously: spam sending, launch of Denial of Service attacks, malware distribution, etc.

• In the local network: it generates a large amount of network activity and consumes bandwidth.

It reduces the security level of the computer: it notifies the attacker that the computer has been compromised and is ready to be used maliciously; it awaits remote-control orders received through IRC; it changes system permissions, decreasing the security level.

It uses stealth techniques to avoid being detected by the user:

• It deletes the original file from which it was run once it is installed on the computer.

Gaobot.PFN uses the following propagation or distribution methods:

• Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
• Via Internet, exploiting remote vulnerabilities: attacking random IP addresses, in which it tries to insert a copy of itself by exploiting one or more vulnerabilities.
• Computer networks (mapped drives): it creates copies of itself in mapped drives.
• Computer networks (shared resources): it creates copies of itself in shared network resources to which it has access.