MessageLabs: 90.4 percent of e-mail was spam this month

Symantec's May 2009 MessageLabs Intelligence report reveals other disturbing trends, as well. Rather than just hijack disreputable Web sites, cybercriminals now favor older and well-established domains to host their malware. The report says 84.6 percent of all domains blocked for malicious content are more than a year old. One type of domain now especially vulnerable to threats is social networking, since most of the sites' content is created by users.

"Spammers using better-known and thus more widely trusted Web sites to host malware is reminiscent of the spammers who rely on well-known Web mail and social networking environments to host spam content," said Paul Wood, Symantec's MessageLabs Intelligence senior analyst. "The trustworthy older domains can be compromised through SQL injection attacks while newer sites are more likely to be flagged as suspicious--a temporary site set up with the sole purpose of distributing spam and malware--and thus faster to get shut down."