Game mods are a minefield of adware, malware, and outright rootkits that compromise PCs. The Minecraft developers messed up a long time ago by doing two things. Not making mods easy to use and not having an official mod repository that offers safe downloads. Even the decent sites offering mod downloads have issues with ads laden with malware.
Further to this: mods are so hard that some people use a mod launcher. This replaces the official Mojang Minecraft launcher. But part of the role of the launcher is to log on the player. These alternative launchers just ask the player for their Minecraft username and password! And this is just what the community accepts.
http://www.reddit.com/r/Minecraft/comments/30orgd/is_there_a...
Are Minecraft mods actually securely implemented?
Could a nefarious mod that didn't include a launcher still read the user/pass out of RAM?
Re:Many ways of malware persistence
by joecarpenter on Tuesday May 05, 2015 @10:37PM
(#9496304)
Mod is just a JAR file that's loaded into Minecraft process. So yeah, no protection whatsoever.
One computer is a Windows7 PC with UAC disabled (unfortunately), so I had to do some deep dives into the registry to clean it. The other was a Mac with Yosemite, and that was so messed up we had to take it to the Apple Store for a wipe and reinstall.
I've tried to coach my kids on downloading and installing things, but when friends come over to play Minecraft it's like they forget everything.