Microsoft has taken aim at a rogue antivirus program called Internet Antivirus Pro.

The company’s latest update to its Windows Malicious Software Removal Tool, (MSRT) released Tuesday, adds detection for this dubious program, which masquerades as security software.

Like all of these rogue antivirus products, Internet Antivirus Pro tries to trick victims into installing the software. It pops up a fake warning message and then pretends to scan the victim’s computer. But instead of scanning for malicious software, Internet Antivirus downloads password-stealing software that looks for FTP user names and passwords, presumably so that its creators can install their software on Web servers.

Internet Antivirus installs a browser component that displays fake messages, and it also pops up a fake Windows Security Center, Microsoft said in a blog posting Tuesday.