Security can do little when people are giving attackers direct access to their machines by installing viruses/trojans themselves.
This was not random effort - it was coordinated attack, and honestly - it may sound harsh now - but Op if you were dealing with HUGE amount of BTC you should be more aware of potential dangers.
This whole - we offer you a job - just install some software on your machine, scam it widely known. I've seen some people lost their bitcointalk accounts in similar attack.