In the former case, the Klez worm has been circulating since mid-April. I've seen virus intercepts go from a base of 6-24 daily (averaging ~12) Jan - Apr 15, to a constant stairstup up, now currently averaging 250 intercepts daily. Absolutely no sign of it trailing off. We've watched people get infected multiple times.
References:
- [link|http://www.symantec.com/avcenter/venc/data/w32.klez.h@mm.html|Symantec W32.Klez.H@mm]. You'll find a scanning tool here. Check the Windows forum for a post of Grygus's as well.
- [link|http://www.wired.com/news/technology/0,1282,52174,00.html|Wired: Don't believe the "from" line].