I first got this false positive about a week ago. I’ve submitted it to avast!, but so far, it’s still detected. Of course I’ve excluded it, but I fail to understand why this FP isn’t getting resolved. I’ve submitted dozens of FPs to Avira, and they’re always fixed within hours. (Maybe because they have so much practice at it!)
Whilst avast and gdata detect this (counts as one) as it is the same signature detection win32:Malware-gen (generic detection), the other two detections are packer based and or heuristic which are more prone to error.
I have submitted the MsgBox.exe file for further analysis.