Microsoft Tuesday announced it is buying Bucharest, Romania-based antivirus software vendor GeCAD Software for an undisclosed price, making it clear that the Redmond giant intends to enter the antivirus market.

In a press release issued with little fanfare today, Microsoft said it has signed a definitive agreement to purchase GeCAD Software, which makes the RAV AntiVirus line of products for Windows and Linux operating systems and applications that include Microsoft Exchange and Novell GroupWise. Microsoft said it's buying GeCAD, which is little known in the U.S., so that Microsoft can provide "antivirus solutions for Microsoft products and services."

In a press release, Microsoft also emphasized that the GeCAD acquisition may also be of benefit to "third-party antivirus vendors so they can provide customers with increasingly secure and comprehensive levels of virus protection."

Microsoft's senior director in the security business unit, Jonathan Perera, said Microsoft wants to buy GeCAD for its antivirus engine and signature-updating technology. "Microsoft will be making antivirus solutions available to customers in the future," said Perera, declining to specify exactly when that would be. "We'll provide fee-based antivirus services at some point."

However, Perera indicated that other antivirus software companies - the largest today are Symantec and Network Associates - need not feel threatened by Microsoft's interest in the antivirus software business. "We will continue to recommend that customers buy antivirus software from third parties," he said.

He said Microsoft will make changes in future editions of its operating system - and most likely, to the current Windows XP operating system as well - to facilitate the use of antivirus software in certain ways. Microsoft is developing a so-called "antivirus mini-filter" that is expected to be added to both XP and forthcoming products as a platform component for running antivirus software. "It will allow multiple antivirus engines to run more efficiently," Perera said.

Whether third-party antivirus software would have to support the so-called "antivirus mini-filter" for antivirus software to run on future Microsoft products at all was a question Perera said he couldn't answer definitively.