Never got a so called virus from there, even from freestuff utilities.
Chances are that same part of the program code can appear as a viral code, while it's a legitimate way to accomplish some routines; this advice is even told by antivirus makers, and generally (legitimate) software writers explain why their programs can be catched as viruses.
If I remember correctly, there was at least one case here when a program scanned by an AV was being told to be infected, while its programmer stated from the first time he released it it could be sensed as a virus (can't remember which program, sorry).

Obviously, if the author doesn't say anything related in his informations, best thing to do is to contact the store admins.