Is there a word for the bad smell coming from socks?

Solution 1:

My answer will probably be down-voted, but here goes anyway.

The problem of sweaty feet is called plantar hyperhydrosis. The phenomenon is, strictly speaking, the problem of having overly sweaty feet. Sweat, or perspiration, does not have an immediate olfactory property (at least not that I'm aware of), but it does emit an unpleasant olfactory component not long after it is exposed to the air after soaking one's socks, for example.

From the little I've read on this far-from-uncommon phenomenon, the technical term plantar hyperhidrosis can also be used to describe the egregious smell emanating from the perspiration being wicked by the socks. The bacteria in the moisture-laden socks mix with the air (and often with the heat generated by exercise and by the temperature at the time) and begin to do their thing. P.U.!

Solution 2:

Cheesey probably gets closest.