We’ve received a new variant of Backdoor.Win32.Wootbot, an IRC Trojan. The file is detected as Backdoor.Win32.Wootbot.gen, but contains an additional function: it will penetrate machines with MySQL server installed.
When the malicious program launches it connects to one of a range of IRC servers where it listens for commands, including command to start propagating. Then it scans a given range of IP addresses and if it finds an open MySQL server port on one of the addresses, the program tries to gain administrator access. It does this by bruteforcing the administrator password using a list of passwords coded into the malicious program. If it succeeds, the worm sends its body to the victim machine, penetrating via a vulnerability which was identified in the middle of 2004, and launches itself on the victim machine.
In addition to its propagation routine, the malicious code has standard functions of IRC backdoors, which will give the remote malicious user almost complete control over the victim machine. The worm opens four ports, port 69 and three chosen at random.
Internet Storm Center estimates that several thousand machines have already been infected.
The malicious program doesn’t exploit any vulnerability for the initial connection to MySQL server. Bacause of this, administrators can protect their servers simply by choosing a strong password.