According to PestPatrol, this false positive has been removed asap!
Now it is the zipdll.dll file that comes with Spybot-Search&Destroy, which contains an explout according to PestPatrol. There is no exploit publically known, as you can look up for example here. The only thing I could find is a bug, but that is 1. no reason to remove a file, as every software contains bugs, and 2. the bug is existing in other versions of this zipdll.dll file - that get not detected - too.
If you are as annoyed as me about this repeated event of a false positive in Spybot-S&D, I would suggest you contact some people at PestPatrol, demanding an explanation that I myself didn't receive yet.