The compression algorithms used to create compressed archives are well known and used by many different software packages, as well as by those that distribute virus/trojans/worms, etc. These algorithms create 'patterns' in the compressed file/image, and these patterns can look similar between legit and bogus files.
As such, scanning software needs to be 'smart' and adaptive in order to detect/flag the bogus patterns/files, while not giving false positives to the legit ones. Its a challenging task, for sure. To make things a bit more complicated, some scanning software vendors allow the user (corporate entities usually) to adjust the 'sensitivity' to these patterns in order to be more rigorous in detection, which can trigger even more false positives.
I've used Pete's FSUIPC pretty much since its inception, and have never encountered any form of actual virus/trojan/worm/etc in any of his deliverables. If you are getting alerts on his files, and you are sure of the source of the files, then I would suggest that the scanner is being overly cautious triggering on a pattern, and giving false alarms.
The compression algorithms used to create compressed archives are well known and used by many different software packages, as well as by those that distribute virus/trojans/worms, etc. These algorithms create 'patterns' in the compressed file/image, and these patterns can look similar between legit and bogus files. As such, scanning software needs to be 'smart' and adaptive in order to detect/flag the bogus patterns/files, while not giving false positives to the legit ones. Its a challenging task, for sure. To make things a bit more complicated, some scanning software vendors allow the user (corporate entities usually) to adjust the 'sensitivity' to these patterns in order to be more rigorous in detection, which can trigger even more false positives. I've used Pete's FSUIPC pretty much since its inception, and have never encountered any form of actual virus/trojan/worm/etc in any of his deliverables. If you are getting alerts on his files, and you are sure of the source of the files, then I would suggest that the scanner is being overly cautious triggering on a pattern, and giving false alarms.