What about this question? It's discussing worm infections rather than viruses but it's all malware at the end of the day.

[How do I deal with the removal/eradication of an unknown worm on our network?][1]


  [1]: http://serverfault.com/questions/339552/how-do-i-deal-with-the-removal-eradication-of-an-unknown-worm-on-our-network