A lot of gaming communities that are migrating over are flowing to the aur for their community tools.

Wasn't there malware found in the AUR just last week?

For Linux newbs, AUR is the Arch User Repository where anyone can post packages and scripts. It's highly recommended to NOT trust anything on there due to the risk of malware. If you don't use Arch and stick to your distro's application manager you don't have to worry about it