Transmission, one of the most used non-commercial BitTorrent clients, has a vulnerability that allows outsiders to gain control over people’s computers. The flaw affects users who have remote control enabled with the default password. The vulnerability was revealed by a Google researcher, who plans to disclose similar remote code execution flaws in other torrent clients as well.
Source: BitTorrent Client Transmission Suffers Remote Takeover Vulnerability – TorrentFreak