For me the setup automatically removed the obvious answers. If someone is testing me and it seems the answer would seem obvious to most people then that's a red flag that the obvious answer is probably wrong. and I need to think about the question carefully.

two four eight....so my first guess was
one four eight...he would have said "fits my rule" and I would have guessed his rule was the number of letters for each number increases by one....and he would have said "not my rule".

My second guess was correct as I listened to 10 rapid guesses in a row that seem to only have two things in common...they were all in ascending order and they were double the previous number. He said the doubling was not his rule so that left one answer....ascending order.

MilkmanDan said:

I would have said "16 32 64" first, and "3 9 27" next. Those both would be leading me further down the trap of thinking in terms of a sequence/pattern rather than just a 'rule'. In computer science it is actually important to test how an algorithm reacts to being fed just bizarre, off the wall inputs -- but you're going to test "sane" stuff first. Human nature.

CryptoLocker Virus Explained - Scary Stuff

Grimm

says...

If I was a hacker I would feel fairly confident that at least 95% of PC users would have no idea what you are talking about.

VoodooV

said:

depending on how much data you have, this actually should be relatively easy to spot/stop.

It takes a while to encrypt a lot of data. With so many people using torrenting more and more to download large video files. Its going to take a long time for it to encrypt all of that. Now yeah, if you just have a bunch of spreadsheets and word documents in your my docs folder, yeah you're probably fucked. But IMO, you shouldn't keep small docs like that on your computer, you keep them on a flash drive not always connected to your computer. Just following with the idea that nothing critically important should be connected 24/7 to the internet anyway.

If you see your hard drive active non-stop even when you're not doing anything, that's your first clue something is amiss.