Virus numbers hit 33-month high: Sophos

Zafi-B continues to hold the top spot for most frequently encountered viruses, for the third month in a row.

The monthly virus and hoax report found Netsky-P gained the number two spot for August, followed by MyDoom-O, Netsky-D and Netsky-Z.

The report, which was put together by software vendor Sophos, looked at the top 10 viruses and hoaxes that businesses battled worldwide during August.

There were more than 1200 new viruses detected during the month, with Sophos estimating that more than nine percent of emails during August were viral. This was the highest number of new viruses seen in a single month since December 2001, according to a statement from Sophos.

Carole Theriault, a security consultant at Sophos, said that Zafi-B didn't look like it was going to fade into obscurity anytime soon.

However, new viruses weren't making it into this month's top 10.

"The entire top 10 is made [up] of viruses which have been doing the rounds for weeks if not months," Theriault said. "A few pesky Netsky variants are still flying around, despite the arrest of the worm's alleged author a few months ago."