Half a million of PCs infected by e-mail virus : Blackmal.E
Blackmal.E, a virus that was recently released in the wild, will be releasing its payload to more then 500000 servers on February 3rd if we can trust the evidence from a public web counter.
When the worm is executed on the 3rd day of every month, it will destroy all files with the following extensions by overwriting them: *.doc, *.xls , *.mdb , *.mde , *.ppt , *.pps , *.zip , *.rar , *.pdf , *.psd , *.dmp
If you got this worm and your AV can't get rid of it, you can always try this free removal tool from Symantec.
For more detail, check this Security Focus article out.