Virus rate rise continues

1 Nov 2005

Just over one in five emails arriving into Irish inboxes last month carried a virus, new figures reveal. October’s infection rate of 18.31pc surpasses the previous high of 15.72pc recorded one month earlier.

The statistics, published today by the email and hosting provider IE Internet, show this is the fourth month in succession that Irish virus rates have risen. Prior to September’s figures, the rate was 13.04pc during August and 9.30pc for the month of July.

October has been the worst month yet for virus attacks by some margin. However, these figures refer to the total volume of viruses in circulation. The actual rate of infection may be lower as emails carrying a malicious payload could be stopped by antivirus software before having a chance to attack individual users’ PCs.

Four of the top five most commonly found infections were variants of the Mytob worm, according to IE Internet. For the second month running, Mytob.FI was the most prevalent malware, responsible for 18.99pc of the total. Last month it alone accounted for more than a quarter of the total.

The long-established Netsky.P regained second place with 14.81pc of infections. Mytob.DY dropped from second to third with 10.92pc, followed by Mytob.FJ (9.57pc) and Mytob.DJ (9.51pc).

“What we’re seeing in October’s virus stats is multiple Mytob strains fighting to convert their foothold into something bigger,” explained Ken O’Driscoll, technical director with IE Internet. “While Zafi might have been knocked off the top five it still has a considerable presence and it wouldn’t surprise me at all if it reappeared in the top five once a dominant Mytob strain emerges.”

W32/Mytob.FI uses social engineering techniques to trick recipients into opening an attachment containing executable file that arrives by email. According to O’Driscoll, the high rate of infection rate suggests that many users are still opening these attachments. “The vast majority of viruses we stop originate from home users, not businesses,” he told “While a combination of technology and education prevents most business networks from getting infected the same can not be said of the home user. This is probably due to a combination of budgetary and educational factors.”

There was some good news as the rate of spam dropped from 43.83pc in September to 37.83pc, its lowest point since July. O’Driscoll welcomed the continued fall in the spam rate below the 40pc threshold but noted that the current figure is “still an awful lot of spam”.

Concerted efforts to reduce the amount of spam originating in the US appear to be paying off, as the US was found to be the source of 43.61pc of unsolicited commercial email. O’Driscoll cautioned that there was a shift in the pattern of attack but not necessarily a reduction in the problem. “While the number of US spam-friendly internet service providers and networks are very small these days, zombie networks comprising US home users are the reason why the US is still a massive source of spam,” he added.

By Gordon Smith