Update: Beware Swen The Virus

 MessageLabs, the email security company, are warning of a new virus, called variously Gibe or W32/Swen.A-mm. Initial analysis would suggest that this strain is a mass-emailing virus, and is similar to the earlier Gibe strain of viruses, however, there latterly may be sufficient differences to give rise to a new family and further analysis will be required. 
The emails appear to be different, and the attachment name may vary, but has a constant file size (106,496-bytes).
Some file names appear to have random letters in their filename, and others may include the following, in some cases with numbers appended): Install.exe, Patch.exe, Update.exe, upgrade.exe, q433137.exe, q478121.exe, q489667.exe, Q653143.exe, Q734269.exe, q762531.exe, Q818418.exe, Q944661.exe, q963681.exe.
Here’s more info on Swen from ZDNet.