I'm gonna try to explain this in a clearer way.
Avast "finds" a virus in file X (which is not actually a virus, it's a FP). A window pops-up saying that file X is infected with something (usually it just has a "bad rep", according to someone (FileRep: malware is the detection). Another bogus detection might also appear (IDP.Generic or that damn "evo-gen" crap). Then, and this is the real problem, avast goes crazy and starts deleting other files. The first one, Winzip.exe, because the file X was inside a zip file when the bogus detection happened. Then, after that, avast just starts deleting other files A,B,C,D....etc that are located on other folders and have ABSOLUTELY NOTHING TO DO WITH FILE X. Also , these files are all 100% clean files, that have been used millions of times before, without avast detecting anything on them.