A new variant of Forbot exploits two Windows vulnerabilities, targets MySQL and attempts to create an army of zombie PCs that could be used to launch denial-of-service attacks and other mischief.
Lynnfield, Mass.-based antivirus firm Sophos Inc. said W32.Forbot-DY targets MySQL open-source database software on Windows systems connected to the Internet. MySQL is a popular alternative to Microsoft's SQL Server database software, and Sophos estimated there are more than 5 million installations globally.
"System administrators should ensure that the computers under their care are properly protected with the latest antivirus software, sensible firewall configurations and up-to-date security patches," Graham Cluley, senior technology consultant for Sophos, said in a statement. "If you take the necessary steps then malicious malware will find it as hard to spread as frozen butter."
He added: "The Forbot worm uses brute force to try and break into systems with weak passwords. The message to system administrators is clear: Beef up your passwords now to stop these kinds of attacks from being possible."
The MySQL Web site has posted further details on the threat, as has the Bethesda, Md.-based Internet Storm Center (ISC). According to the ISC, the malicious code has infected a few thousand systems so far.
Infected systems will connect to an Internet Relay Chat (IRC) server, the ISC said. The IRC server will then instruct the zombie machines to scan various networks for other vulnerable MySQL servers.