Mytob viruses were the most reported malware during March. Monthly virus reports released this week confirm that Mytob.c worm remained the top malware of the month. NetSky.t is in second place, followed by the LovGate.w virus. Many of the rest of the top 20 were Mytob variants.

"At this point one would think that computer users would have gotten the message, but it obviously bears repeating: treat unsolicited email attachments with extreme caution," said Ron O'Brien, senior security analyst at Sophos, which has U.S. headquarters in Lynnfield, Mass. "Cybercriminals prey on the naïve and unsuspecting, and getting infected by malware means you are at risk of getting ripped off."