A new variant of the Keydnap backdoor has been added to the Transmission torrent client. Malware was signed using an Apple developer certificate that appears to be owned by Igor Shaderkin, who has several medical apps in the iOS App Store. Torrent apps can be a huge hole in your Macs security if they arent properly configured or have vulnerabilities that can be attacked remotely. Any app that opens up your computer to remote connections by strangers is a potentially highly dangerous app.”]
Source: https://blog.malwarebytes.com/threat-analysis/2016/09/transmission-hijacked-again-to-spread-malware/