Op still haven't told how he got infected.
Now I'm all paranoid.
Damn inconvenience of additional security.
Most likely it was a trojan binded to some executable file that OP run. Also it can be a 0-day exploit on system or some misconfiguration of computer such as reused passwords or something.
I suppose it was a windows operating system?
Likely Windows, because to infect Windows you need to double click file. To infect Linux you need to use SU. It is a sanity check and dumbness filter.
Message to the thief if he is reading this: I will launder the coins for a small fee. Additional guarantees available. Price and other terms negotiable. Also I can give instructions for do-it-yourself laundering.
OP is not going to pay me for my great knowledge!