Tests show limits of virus scanners

The only package that spotted every single virus was the Norwegian software Norman Virus Control. Virus Bulletin conducts the tests every six months and last time out two packages - Esass Thunderbyte and Frisk Software's F-Prot - scored 100 per cent. The tests are independent and requires no fee from the software vendor.

"We were really surprised," said Megan Skinner, assistant editor of the Abingdon, Oxon.-based journal. "But there are so many new viruses and the increase in macro viruses has been amazing."

However, Skinner said the results were not cause for alarm. "What's encouraging is that every single one we tested scored over 90 per cent and anti-virus vendors seem to be working harder than ever to get the new viruses."

Two big guns had close to perfect scores: Symantec Norton AntiVirus scored 99.8 per cent while Dr Solomon's recorded 98.7 per cent.

However, Dr. Solomon's senior technology consultant David Emm said that the regular monthly updates issued by most anti-virus vendors made it impossible to test perfectly. "It's down to version numbers," Em said. "Our test was on a product that was just about to be updated. Any virus worth its salt should detect viruses in the wild."