Almost one in four Irish emails last month were infected with a virus, by far the highest total yet recorded. Data released today by IE Internet shows that 23.43pc of emails circulating in December contained an attachment with malicious code.
This is a sharp rise on the previous month’s rate of 16.51pc and is attributable to two factors: the first was the launch of Sober.Z in November, which was extremely widespread. In November it accounted for 15.72pc of the total volume of infected email – by the end of the following month this figure had mushroomed to 45.2pc of the total, eclipsing all other viruses combined.
Sober.Z was disguised in emails purporting to come from the FBI or CIA, informing the recipient that their internet use was being monitored and that a list of questions was included in the text attachment. On opening, this file launched the worm.
The second reason for the higher than usual infection rate is because many businesses close for several days at Christmas, giving viruses a chance to spread widely before being caught by filtering software or alert IT managers. The holiday season also means that fewer genuine emails are sent, so that the volume of viruses tends to be a higher than usual proportion of the total. This year’s total is nonetheless worrying when put in context – the total for the December 2004 was just 9.92pc.
At the beginning of December Ken O’Driscoll, technical director with IE Internet, warned that Sober.Z looked likely to cause a rise in virus infections and it took just one month for his prediction to be proved correct.
The rate of spam fell slightly during the month, but was high overall, at 38.93pc down from 41.99pc recorded in November. Interestingly spam levels were very similar to those recorded in December 2004, at 39.35pc.
By Gordon Smith