What is it?
W32.Beagle.AG@mm - winxp.exe

What does it do?
W32.Beagle.AG@mm is a mass-mailing worm that uses its own SMTP engine to spread through email and opens a backdoor on TCP port 1080.

The subject line, body, and attachment name of the email vary. The attachment will have a .com, .cpl, .exe, .scr, or .zip file extension. If the file attachment is a .zip file, it will be password protected. This zip file will be detected as W32.Beagle@mm!zip .

The worm is packed with PeX.

Removal:
Symantec has the full dirt ( Here )