A newly identified Mac OS X Trojan bundles a component that leverages the processing power of video cards (GPUs) to generate Bitcoins, a popular type of virtual currency.
The new Trojan was dubbed DevilRobber by antivirus vendors and is being distributed together with several software applications via BitTorrent sites.
"This malware is complex, and performs many operations," security researchers from Mac antivirus vendor Intego warned. "It is a combination of several types of malware: It is a Trojan horse, since it is hidden inside other applications; it is a backdoor, as it opens ports and can accept commands from command and control servers; it is a stealer, as it steals data and Bitcoin virtual money; and it is a spyware, as it sends personal data to remote servers," they explained.
The Bitcoin mining program that DevilRobber installs on infected computers is called DiabloMiner and is a legitimate Java-based application used in the virtual currency's production.
Bitcoin is a form of virtual cash that can be exchanged by users without the need for an intermediary bank or payment service. Bitcoins are actually cryptographic hashes that get generated piece by piece using specialized programs like DiabloMiner, according to a public algorithm.
One Bitcoin is currently valued at around US$3.20, and it is a good source of profit for both Bitcoin miners, who legitimately use their computer resources to generate them, and cybercriminals who steal them.
The DevilRobber trojan steals processing power, which can lead to slow computer performance, as well as actual Bitcoins, which are kept in virtual wallets on the victim's machine.
"OSX/Miner-D [DevilRobber] also spies on you by taking screen captures and stealing your usernames and passwords," warned Graham Cluley, a senior technology consultant at antivirus vendor Sophos.
"In addition, it runs a script that copies information to a file called dump.txt regarding truecrypt data, Vidalia (TOR plugin for Firefox), your Safari browsing history and .bash_history," he added.
So far, the Trojan has been detected in a BitTorrent download for GraphicConverter version 7.4, an image editing application for Mac OS X. However, this doesn't mean that there aren't similarly Trojanized torrents out there.
"Clearly, Mac users -- like their Windows cousins -- should practice safe computing and only download software from official websites and legitimate download services," Cluley said. He also stressed that Mac users should install an antivirus program, which is not hard to do and costs nothing.
There are several providers of free antivirus solutions for Mac and all of their solutions are more capable than Mac OS X's default anti-malware defense mechanism, which some Trojans already bypass or even disable.