Mytob is a worm used by hackers to gather personal and financial information through phishing, a form of e-mail fraud where the perpetrator sends out legitimate-looking messages that appear to come from well-known and trustworthy Web sites. Since Mytob first originated in February 2005, numerous variants have emerged. Some forms of the worm cause infected computers to send out e-mail messages containing a link to a Web site that hosts rogue programming code. Earlier versions appear as e-mail attachments.
After Mytob has been downloaded to a computer, it forwards itself to all the e-mail addresses gathered from the infected computer. In addition to exposing critical information stored in personal and business computers, Mytob can convert infected computers into so-called zombies for the purpose of spreading spam. Some variants disable registry editing tools, firewalls, anti-spyware programs, and anti-virus software.
Mytob can infect systems running Microsoft Windows 95, 98, 2000, Me (Millennium Edition), NT, Server 2003, and XP.