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

Gaobot.NMC 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 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 opens one or more ports to allow remote access to the computer and takes action that compromises user confidentiality; 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 uses techniques included in its code to hide itself while it is active.

It uses several methods in order to avoid detection by antivirus companies:

• It terminates its own execution if it detects that a debugging program is active.

Gaobot.NMC 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.