Compromised websites are staying infected longer. Some infected sites stay up and running for as long as two months, according to an annual report from web security firm ScanSafe.

ScanSafe's Annual Global Threat report (published on Monday) also revealed that web threats including viruses, Trojans, and password stealers are becoming more prevalent, with a 61 per cent increase in malware during the second half of 2007.

Twenty-one per cent of all the malware blocked by ScanSafe last year was undetected by signature-based detection tools. ScanSafe, ike other net filtering firms such as MessageLabs, uses signature-based detection tools from third parties as a component of its web filtering services.

As well as discovering a greater variety of crud, ScanSafe found the amount of time a website hosting malicious code remains live increased during the second half of 2007. Malware on infected sites remained live for an average of 29 days in 2H07, up 62 per cent from the first half of the year.

Forms of malware undetected by scanner packages have an even a longer shelf life once they compromise a site, persisting an average of 61 days in the second half of 2007. ®

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