Worm tops virus charts for 13th consecutive month. Klez has been branded the most persistent worm ever to plague internet users, after spending a record 13 months in antivirus vendors’ top 10 charts. Chris Wraight, technology consultant at antivirus firm Sophos, said Klez victims had “no excuse” for not updating their antivirus software. “In its various guises, Klez has now been hanging around the chart for 13 months, making it the most persistent worm ever,” he said. “People infected by Klez cannot have updated their virus protection in quite some time.” Klez was the most frequently occurring infection in February, accounting for almost 14 per cent of the month’s total incidents, according to figures from Sophos. The research also found that 541 previously unknown viruses, worms and Trojans emerged during last month. Full Story