Netsky: Worst Virus Of 2004

U.K.-based Sophos spotted more than 10,700 new viruses, worms, and Trojan horses during the 12-month span of November 2003, to November 2004, a 51.8 percent increase over the same period a year ago. Top on that list, and accounting for over half of 2004's virus attacks, was the Netsky worm family, which so far has cranked out more than 30 variants.

"2004 was the year of the Netsky," said Graham Cluley, a Sophos senior technology consultant. Netsky.p, which debuted in March, ranked as Sophos' number one virus by causing 22.6 percent of all virus incidents. Altogether, five Netsky variations made it in the year's top 10.

Although German teen Sven Jaschan, who faces trial for allegedly creating the original Netsky worms, was arrested months ago, variants continue to plague users, said Cluley, who oddly enough, laid the blame on users not hackers.

"It's simply shocking that viruses like Netsky.p are still infecting computers, months after they were first protected against by anti-virus companies," he said. "Anyone still being infected by these worms is demonstrating a worrying lack of concern for their PC's health."

Other viruses and worms in 2004's parade of malicious code criminals include Zafi.b (#2, accounting for 18.8 percent of all attacks), Sasser (#3, 14.2 percent), and MyDoom.a (#7, 2.4 percent).