New Mac OS X malware surfaces

A new worm is threatening to turn Apple systems rotten

Apple Mac users are being warned to keep a close eye on their systems following the discovery of new malware for Mac OS X.

The malicious 'HellRTS' tool has been spotted as a proof-of-concept sample. No active exploits or attacks have been spotted, but experts have warned that samples of the malware have been widely circulating online.

Mac OS X security specialist Intego said that the malware can be spread through a Trojan download or a web-based exploit.

On installation, the software renames itself after common files and applications as well as adding a copy of itself to the user's start-up folder.

The tool allows an attacker to remotely access infected machines as well as remotely install applications and use the infected machines to send emails without user notification.

Intego said that HellRTS is actually a modified version of a malicious application that first appeared for the Mac OS in 2004. The payload is written as a universal binary, so Intel and older PowerPC systems can also be infected.

While still far less common than Windows-based malware, malicious code targeting Mac OS X systems has become more prevalent in recent years.

Experts are increasingly warning Mac users to take basic precautions such as avoiding suspicious email attachments and links, downloading software only from trusted sources and keeping the operating system and all applications current with the latest patches and updates.