Spam levels are back on the rise, says security software firm MessageLabs.
The MessageLabs Intelligence Report for May says spam levels are back on the increase with levels reaching 76.8% of all e-mails in May, levels not experienced since early 2007.
The rise in spam, according to MessageLabs, is due to a change of tactics adopted by the spammers. They are moving further away from a reliance on new and undetectable e-mail attachments, and towards the exploitation of free, mainstream hosted services such as Google Docs, Google Calendar and Microsoft SkyDrive.
"The savvy, intelligent and accurate cybercriminals of today seem to have abandoned the attachments tactic that was so innovative in late 2007, and are now focused on exploiting free hosted applications that have become mainstream in 2008," said Mark Sunner, chief security analyst at MessageLabs.
"The spammers are taking advantage of the fact that these services are free, provide ample bandwidth and are rarely blacklisted. This is one more addition to the growing list of ways the spammers have succeeded in outsmarting traditional detection devices," he said.