Watch Dogs PC players have been infected with a bitcoin miner trojan after using a cracked copy of the game downloaded via Bittorrent, giving hackers access to stolen computing power brute force creating more of the lucrative bitcoin Internet currency.

Playing a game as demanding as Watch Dogs on the PC requires a powerful graphics processing unit (GPU). Therefore gamers, such as those playing Watch Dogs, have become popular targets for underhanded bitcoin miners because of their high-end GPUs.

Using stolen computer resources is a way of making easy cash by increasing computing power for the bitcoin mining software, which is uses it to solve difficult math problems resulting in the person running the software earning more of the digital currency.

Infected GPUs can be used to extract bitcoins, or generate bitcoins via minting. Minting is a process of solving difficult crypted problems the reward of which are 50 bitcoins for a correct block. As of this article's publishing, one bitcoin is worth $567.99.

On May 23, an infected torrent of the popular game Watch Dogs which had the copy-protection removed, had 40,000 users and 18,440 downloads on a single site, in a single day.

Internet forums discussed the torrent package, disguised as being from cracking group SkidRow, after it had installed the Bitcoin miner together with the game. The miner runs via two files in Windows users' AppDataRoamingOaPja folder, slowing down machines with low resources, sucking up about 25 percent of CPU power.

Many sources already removed the infected torrent and action has been taken to track down those behind the attack.

For those who have downloaded Watch Dogs or other applications via torrent or any other pier to pier (p2p) sharing software should check their computer systems for possible infections. They may already have been victimized by a trojan containing a GPU miner, said Catalin Cosoi, chief strategist of BitDefender.

The bitcoin mining attackers are expected to have a limited happy hour, though, because most PC gamers are usually hardware enthusiasts who can easily notice signs of mining on their computers. For instance, graphic cards are normally inaudible, but when under load, they don't stay silent as fans throttle up when the GPU starts crunching numbers.

Since the attack was detected as being associated with one source in the form of a torrent file, torrent users can trace the infected torrent file easily and remove it.