The VirusEye monitoring service run by security firm MessageLabs said the UK has been hit the hardest.
On Friday afternoon (4 October) MessageLabs reported that its virus scanning service had stopped almost 113,000 occurrences of the Bugbear virus worldwide. Some 53,189 of these were in the UK, 9,700 were in Australia and just 6,720 in the USA.
The virus, which originated from Malaysia, has been disrupting e-mail users since 29 September.
Reacting to the impact of Bugbear, Mark Sunner, chief technology officer at MessageLabs, said: "There have been few new viruses in 2002 although levels of virus activity have never been higher."