Older viruses wage war against Windows
Only one new piece of malware was prevalent enough to make it into the 10 most-active viruses last month as users continued to ignore updates, according to anti-virus vendor Sophos.
The Zafi-D virus, which was first discovered late last year, remains at the top of Sophos' top 10 virus list, accounting for 46.6 percent of all infections in April 2005. Mytob-Z was the only virus discovered in April to make the top 10 and was responsible for 1.3 percent of all infections.
Carole Theriault, security consultant at Sophos, said that variants of Zafi -- Zafi-B is in third position, accounting for 4.5 percent of all infections -- have succeeded because they are multi-lingual.
"Old viruses were still taking advantage of poorly protected computers in April The Zafi family of viruses accounts for over 50 percent of all the viruses reported Perhaps the success of these worms lies in their ability to spread in multiple languages, catching out unwary users all over the world," said Theriault.
According to Theriault, although the Mytob virus has infected a relatively small number of people, it is "nasty".
