Sophos, a world leader in protecting businesses against spam and viruses, is warning of a new worm called MyDoom (W32/MyDoom). Also known as Novarg or Mimail-R, the worm spreads via email, using a variety of technical-sounding subject lines and attachment names. If the attached file is launched, and the worm activated, the infected computer's hard disk is harvested by the worm for more email addresses to send itself to. The worm opens a backdoor onto infected computers which allows hackers to gain access.
The worm also spreads via the KaZaA file sharing network, and is believed to have been designed to launch a denial of service (DoS) attack from infected computers (known as zombies) against SCO's website.
"MyDoom is unlike many other mass-mailing worms we have seen in the past, because it does not try to seduce users into opening the attachment by offering sexy pictures of celebrities or private messages," said Graham Cluley, senior technology consultant for Sophos. "MyDoom can pose as a technical-sounding message, claiming that the email body has been put in a attached file. Of course, if you launch that file you are potentially putting your data and computer straight into the hands of hackers."
"When the MyDoom worm forwards itself via email, it can create its attachment in either Windows executable or Zip file format. It is possible the worm's author did this in an attempt to bypass company filters which try and block EXE files from reaching their users from the outside world," continued Cluley.