Security vendor Sophos has found an old Windows backdoor Trojan that has been reconfigured for MacOS X systems.
The trojan, called Blackhole Remote Access Trojan (RAT), appeared to be an early experiment, according to Sophos security advisor Chester Wisniewski.
“As even the malware itself admits, it is not yet finished, but it could be indicative of more underground programmers taking note of Apple's increasing market share,” the researcher said.
The Trojan relies on social engineering to attempt to slip past Apple’s application signing process, prompting a user to type in their Administrator Password in order to install it.
Wisniewski said the Trojan’s functions include placing text files on the desktop, sending commands to restart, shutdown or sleep, running arbitrary shell commands, creating a window that forces a user to reboot, and sending viewed URLs to an open website.

Security vendors have long talked of the impending rise of malware for Macs, but so far the platform has failed to attract malware writers en masse.
Security giant McAfee had avoided releasing a MacOS X security product but last year released one.
Apple last year reportedly issued a patch that dealt with another Trojan, HellRTS.