Something I caught from work, that has infected every fucking executable on my main computer.
Norton AV didn't bother telling me about it, but AVG caught it.
I'd been wondering what the hell svchost.exe was that was running on all the machines at work for at least the last 7 months (all of which run with Norton AV on all the time), and was now showing up on my home machine. I left my job last month and so I started to purge old work stuff off my machine and decided to track down what it was (yeah, kind of like breaking up with your girlfriend and discovering that your "stress eczema" is actually the clap).
This little beauty launches itself as a hardware service called Power Manager, every time any infected executable runs it resets itself up. You have to use a task killing app to actually get rid of the processes (since windows is braindead and won't let you do that by default). It encrypts a portion of every executable it is in, and so the only solution is to delete ALL infected files - yes even the system ones and reinstall windows and all the damn apps.
I now support the public stoning on Virus writers.