An anonymous reader writes: Recently I was working on a system that had been infected by spyware. The system was up to date with high priority patches (automatic updates were turned on and active), it was running an "Enterprise" anti-virus solution from a major vendor, yet had allowed an infestation to enter it simply by visitng a website (according to the user).
One of the first things I did was to install Windows Defender, updated it and ran a scan. WD identified some malicious programs and claimed to have removed them. However, these programs were still present. Once the active malicious programs had been removed by booting from a live CD, I installed Spybot Search and Destroy and scanned once more. Spybot S&D found a few more files and, at the point that I asked Spybot S&D to delete them, Windows Defender popped up a window asking to send information about one of these files to Microsoft. This is either a massive coincidence, or Windows Defender is watching Spybot.