"Less then two weeks ago, we covered the significant security flaw in AVG’s Web TuneUp software, and the company’s back and forth with Google security researcher, Tavis Ormandy. Ormandy has found a new set of bugs in Trend Micro’s Windows anti-virus product — bugs that are, if anything, worse than what we saw with AVG. Unlike the AVG problems, which involved a (technically) optional toolbar, installing Trend Micro’s antivirus software is a significant security risk.
Ormandy found that installing Trend Micro Antivirus also installed a password manager. This software automatically launches on startup and has a “feature” that allows for arbitrary code execution. Like AVG, Trend Micro responded in short order — but the company’s response apparently left much to be desired."