Research commissioned by application switching provider Radware found that 70% of the 50 small businesses it monitored experienced more than 1,500 attacks over a two-week period in August - largely because of the outbreak of the SoBig virus.

And with web-based distributed applications becoming more pervasive, the majority of security threats facing corporations will be at the application level across port 80, the research warned.

Radware's regional director for northern Europe, Anthony Crowley, said in a statement: "Businesses that fail to manage the soaring number of virus attacks clogging their networks risk paralysis.

'It does not bode well for larger companies that even small enterprises are being attacked with such venom. The reality is that attacks will always happen, so businesses need to minimise their impact.'