Name :	Mytob.em
Category:	Malware
Type:	Email-Worm, Net-Worm, Backdoor
Platform:	W32

This Mytob variant was found at the beginning of May 2006. It sends e-mail messages with a URL to the worm's file that is located on a possibly hacked computer.

Computers infected by the worm send e-mail messages with a URL that points to the worm's file. The worm fakes (obfuscates) the download URL and inserts the user's domain name and e-mail address to the message body to make the message look trustworthy. Here's a sample of a message:

Dear Valued Member,

According to our terms of services, you will have to confirm your e-mail by the following link, or your account will be suspended within 24 hours for security reasons.

http://www.*domain*.com/confirm.php?account=*e-mail_address*

After following the instructions in the sheet, your account will not be interrupted and will continue as normal.

Thanks for your attention to this request. We apologize for any inconvenience.

Sincerely, *Domain* Abuse Department

where *domain* is the domain name of the recipient and *e-mail_address* is the recipient's e-mail address. The URL points to the file named Confirmation_Sheet.pif that is located on a possibly hacked computer. When a user downloads and runs an infected file, his computer becomes infected and the worm starts to spread from it.