Although overall levels of spam went down 1.5 per cent during the third quarter, the number of messages harbouring malware soared according to Kaspersky Lab’s quarterly spam report.
At the start of the quarter 6.3 per cent of emails carried malicious attachments, the highest percentage to date.
During the quarter as a whole malicious spam averaged 4.6 per cent compared with 1.9 per cent in second quarter.
Fake messages from social networking sites and online games sites accounted for most of the spam.
Kaspersky Lab put down the increase in malicious spam to a worrying trend for spammers and cybercriminals to work together, while the fall in the total amount of spam followed the closure of control centres associated with the Pushdo and Cutwail botnets.
Kaspersky Lab’s online news network, Threatpost, recently won a 2010 Forrester Groundswell Award in the Business-to-Business “Spreading” category.