W32Sobig worm

The current virus which is circulating is called the W32Sobig worm.
It actually comes in multiple flavors that are identified by adding the letters a-f after the name.
The variant W32.Sobig.F@mm was discovered on August 18^th.

Due to the number of submissions received from customers, Symantec Security Response has upgraded this threat to a Category 4 from a Category 3 threat as of August 21, 2003.

This worm is causing, clean uninfected computers to receive Virus warnings from recipients to whom they have not sent any E-mails either lately or ever. The following is an excerpt from Symantec’s document about this worm. (Please review possible solution mentioned at the end of this Document)

The worm uses its own SMTP engine to propagate and attempts to create a copy of itself on accessible network shares, but fails due to bugs in the code.

Email routine details
The email message has the following characteristics:

From: Spoofed address (which means that the sender in the "From" field is most likely not the real sender). The worm may also use the address ^{admin@internet.com as the sender.}