After seeing a 70% drop off in spam with the demise of the McColo network in November 2008, levels are on the rise again and Google has warned that viruses sent via email and in blended attacks continue to be a serious threat.
Citing data drawn from its Postini Message Security network, which processes over two billion enterprise email connections per day, Google reports that spam levels have rebounded and are up by 156% since spammers lost McColo.
“Even though virus attachment volumes have been low so far this year, we expect spammers to work hard to rebuild their networks to replace what was lost in the McColo shutdown” Amanda Kleha of the Google Message Security Team blogged yesterday.
Data suggests that spam traffic increased by 25% in 2008 compared with the year before and Google believes the botnet operators are now regrouping before a new onslaught.