Intego categorizes the new Mac malware variant – HellRTS – as low risk, but warns that it can open a backdoor on infected machines running Mac OS X. The backdoor, which Intego calls OSX/HellRTS.D, is a modification of an earlier Mac OS X malware strain that the vendor first identified in 2004.

Intgeo said that, when installed on a Mac, the new malware strain can allow remote users to control infected computers. The firm said that there are no known reports of a Mac being infected by this malware in the wild, as it would need to be installed on a machine via a trojan or through exploiting an application vulnerability.

However, Intego said that the malware variant “is being distributed on a number of forums” in a recent blog posting, which means hackers with nefarious intent could potentially take control of a Mac if the malware were successfully installed.