Well, thank you for the help.
If you played around with BitCoin miners on Windows, check if you were hacked too. I had this start-up item (which I did not set up), and the miner started automatically at system startup:
"C:\Users\<username>\AppData\Roaming\Adobe32\svchost.exe" -o
http://pool.abcpool.co:8332 -u eeax.w1 -p somepass
The only reason I registered here to reach the ABCPool admins with a PM, but I can't do that because of the "newbie-policy" mentioned in this post.