If you have installed the Angry Planes or NoClip mod they contain Malware and you should delete them immediately!
Follow these instructions
1. Go to link above – Follow instructions
2. Download CCleaner and Malwarebytes
-Scan and delete anything that pops up
3. After cleaning or doing Number 1 above restart computer (Check to see if any of the above files have reappeared) then change all online passwords that you have used/logged in with since using the mods.