Across industries, MessageLabs noted an increase in attacks in a particular industry -- retail.

"For the first time, targeted attacks hit the retail sector hardest this month where they increased from a steady monthly average of 0.5 per cent of all attacks over the past two years to 25 per cent in October characterised by a retail organisation that was the intended recipient of three waves of highly targeted spear phishing attacks. In October, 1 in 1.26 million e-mails comprised a targeted attack," the report stated.

The attacks in the industry also targeted specific operational units -- human resources and IT.

"The spear phishing attacks, launched in three waves each one week apart, used social engineering techniques to distribute legitimate-looking e-mails from HR and IT staff of the targeted organisation but in actuality contained malicious attachments," said MessageLabs.

The report theorized that the attackers might be trying to steal client information from the retail industry.