Mods are great for customizing games, particularly PC games. But that doesn’t mean they’re entirely safe. Some people do want to exploit the vulnerability these mods create. It has been found that the popular Angry Planes and No Clip mods for Grand Theft Auto V contain malicious code. A GTA Forums member found a Fade.exe executable in his temporary files folder after Angry Planes mod started to misbehave. It was found to be a keylogger. Other malware found in the mod included a Facebook spam/credential stealing module, a Messenger.com spam/credential stealing module, a UDP flooding module and a keylogger module, a Steam spamming module, and a Twitch spam/credential stealing module.
Source: Ubergizmo