It used to have an evil twin, the Underhanded C Contest [1] where the aim was to make an innocent program also do something evil in such a way that that it can be plausibly denied as accidental when the 'bug' is detected in a code review.
"Used to have"? The underhanded C contest is back!
I'd love to see the converse, where the goal is to write code that looks really malicious but is actually a useful and helpful program -- like an apparent rootkit that actually implements a full webserver.