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

Gaobot.MWL 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.

It sends the gathered information to a remote user by any available means: email, FTP, etc.

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 awaits remote-control orders received through IRC.

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

• It uses techniques included in its code to hide itself while it is active.
• It deletes the original file from which it was run once it is installed on the computer.

Gaobot.MWL 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.
• Email: sending emails that include a copy of itself as an attachment. The computer is infected when the attachment is run.
• 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.