Microsoft has come under fire for naming the developer of a program that can install adware on users\u2019 PCs as one of its Most Valued Professionals.MVPs are people with deep knowledge of Microsoft products who volunteer to answer technical questions for other users or contribute to its software in significant ways. It\u2019s a prestigious recognition, with only about 2,600 MVPs worldwide.Microsoft recently added Cyril Paciullo to its MVP list. He\u2019s the developer of Messenger Plus, a free plug-in that adds some handy features to Microsoft\u2019s Windows Messenger program, like the ability to stack several chat windows together and access them via tabs. But security experts say his software is also a distribution vehicle for Lop, which they describe as a nasty adware program."Bottom line is, Microsoft are rewarding someone that has an active involvement with one of the most maligned names in PC hijacking," said Christopher Boyd, a Microsoft Security MVP who\u2019s also director of malware research for FaceTime Security Labs. "If that isn\u2019t booberific, I don\u2019t know what is," he wrote in his blog.Lop is a family of adware programs\u00a0that will, among other things, generate pop-up advertisements and install misleading icons on a user\u2019s desktop, according to Sunbelt Software, a security company that also noted Paciullo\u2019s MVP award with interest.Messenger Plus does provide users with the option not to\u00a0install its accompanying "sponsor program." But Pacuillo\u2019s involvement with adware makes his MVP appointment questionable and also devalues the program, critics said."Yeah, it now gives you an option as to whether you want to install it or not\u2014but that\u2019s hardly the point, is it?" Boyd wrote in his blog."Note that he does give the option to infect your machine (and quite politely, at that). But it\u2019s still Lop," Sunbelt Software said.Paciullo, who goes by the alias Patchou, could not be reached for comment on Friday. He says in a frequently asked questions section on his website that the sponsor program is not dangerous and can be uninstalled easily. He acknowledges that some adware programs flag his software, but says that\u2019s because they can\u2019t distinguish between "a clean adware solution and nasty spyware."Microsoft also did not immediately comment. Its own malware-protection engine flags Messenger Plus as a threat, according to Boyd.Paciullo is not new to criticism. His software has been a target for another Microsoft Security MVP, Sandi Hardmeier, who runs a blog called Spyware Sucks.Paciullo has made some changes to Messenger Plus in response to Hardmeier\u2019s criticisms, Hardmeier wrote in her blog. Version 3.63, introduced in April, no longer installs a toolbar and resets the browser homepage, she said. But it does generate pop-up windows that try to install Active X controls on a PC, she said, including one that\u2019s known to use rootkits, making it still "malware" in her book.SunBelt\u2019s posting can be located here. Boyd\u2019s posting is here. Hardmeier\u2019s posting is available here.-James Niccolai, IDG News Service (Paris Bureau)This article is posted on our Microsoft Informer page.\u00a0For more news on the Redmond, Wash.-based powerhouse, keep checking in.Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.