Two variants of the Station worm -- also called "Warezov" -- made Sophos' top 10 for the month. According to the U.K.-based vendor, "several hundred" versions of the worm were spammed to users during the month, with the family accounting for more than half of all reported malicious code on some days. The versions grabbed the number three and number six spots on the list.
"This is like a new dog employing old tricks," said Carole Theriault, a Sophos senior security consultant, in a statement. "Stration has made it into the top 10 because it used numerous social engineering tactics and has been aggressively spammed," she said.
"If old-timers like Netsky and Mytob are still getting through users' defenses, it's a sure bet that new malware is doing the same."
Topping Sophos' October list of bad news was Netsky.p, a worm that debuted more than 30 months ago; Mytob.as, which was discovered in June 2005, placed second.