Mac users are at risk from a newly discovered Trojan for Mac OS X, created by by porting an older Linux backdoor Trojan horse onto the Apple operating system.
The Tsunami Trojan is derived from Kaiten, a backdoor Trojan designed to infect Linux machines causing them to 'phone home' for further instructions from an IRC channel.
Early speculation suggests the malware could be used to co-ordinate infected computers in Distributed Denial of Service (DDoS) attacks.
The discovery was reported yesterday by security firm Sophos, when senior technology consultant at Sophos, Graham Cluley, warned:
"Mac users are reminded that even though there is far less malware in existence for Mac OS X than for Windows, that doesn't mean the problem is non-existent.
"We fully expect to see cybercriminals continuing to target poorly protected Mac computers in the future. If the bad guys think they can make money out of infecting and compromising Macs, they will keep trying. My advice to Mac users is simple: don't be a soft target, protect yourself."