I was recently analyzing the sources of ZeuS, ZeroAccess, Carberp and other professional malware and there was one thing which I found weird:
The authors did not use the standard library
std::-functions very frequently when they could have. I mean stuff like
std::cout (for debugging).
My question is why? A lot of tasks could be accomplished easier if they would use these functions. I don't think efficiency was their concern since the speed boost wouldn't be worth the time spend.