Sober Worm Causes Surge In Virus-Infected E-Mail

The number of infected e-mails captured by e-mail security firm Postini rose by 381 percent to 184 million, compared to April, officials said. Fully 78 percent of the e-mails contained the Sober worm.

Sober traffic reached an all-time high from May 3 to May 7, when the percentage of e-mails containing the virus, 14 percent, was higher than the percentage of legitimate e-mails, 13 percent, Postini said.

"Sober worm traffic in May was staggering," Andrew Lochart, senior director of marketing at Postini, said in a statement.

The top three viruses, in order, in May were Sober, Mytob, and Netsky, according to Redwood City, Calif.-based, Postini.