Storm botnet blows itself out

he Storm botnet decreased to just five per cent of its original size during April, but overall web-based malware levels increased by 23.3 per cent, new monitoring data reveals.

MessageLabs' Intelligence Report for April 2008 said that new malicious software removal tools aimed at removing Storm infections were responsible for the sudden reduction in Storm-infected computers.

The security firm now estimates the botnet at approximately 100,000 compromised computers, down from previous estimates of two million.

This is evidenced by a 57 per cent decrease in malware-laden emails distributed by the Storm botnet during April.

However, analysis of web-based malware suggests that 36.1 per cent of interceptions in April were new, an increase of 23.3 per cent since March.

MessageLabs also identified an average of 1,214 new websites per day harbouring malware and other potentially unwanted programs such as spyware and adware, an increase of 619 compared with the previous month.