During August, Netsky-P accounted for 19.9 percent of all malicious software incidents reported, according to a report released Friday by security researcher Sophos. Netsky-P, which remains the most widely spread of the e-mail worms, was.
Just one in 278 e-mails were infected during the month, a significant decrease compared with August 2005 when one in every 50 e-mails circulating were viral, according to Sophos.
Sophos identified a total of 1,998 new threats in August 2006, with Trojan horses accounting for 71.8 percent of those threats.
Netsky-P was followed by, which accounted for 15.8 percent of malicious software reports, while accounted for 8 percent of reports, according to Sophos.
"It is certainly frustrating that such easily beaten threats are still plaguing our e-mail highways," Carole Theriault, a Sophos senior security consultant, said in a statement. "If you use the Internet and don't have proper security measures in place, you are not only endangering your data, you are keeping nasty old timers like Mytob and Netsky worms alive and kicking."
But some industry observers question the usefulness of keeping tabs on how widespread a virus roams, versus other metrics such as the degree in which it affects users' pocketbooks when sensitive data is stolen. Malicious attackers over the years have switched their agenda from .