Trojans designed to steal online gaming account information now account for more than one-third of all malware activity, according to US security management firm Fortinet Technologies.

Although these vociferous attacks threaten individual gaming account holders, Fortinet said this does not mean businesses can rest easy.

"Most of the time, Trojans have integrated functionality so they can accept commands from a remote attacker and download new code to be used for any purpose," said report author Derek Manky, who is a security research engineer at Fortinet.

Two specific online gaming Trojans catapulted to Fortinet’s top 10 threats in April. Since then, the Trojans have moved into second and fourth place on the list.

As a family, the malware is twice as pervasive as the next leading group of insidiously-designed software.