ISO images scanning issue

[RejZoR]

I tried Thorough check of the disk with Archives option as i stated in another thread to test the scan time.
Anyway there seems to be big issue with ISO extraction method.

My Athlon 2400+ (clocked at 3400+, 400MHz Bus),512MB ultra low timed 400MHz DDR (DualChannel) and 200GB Maxtor can handle any RAR or 7zip archive(over 700MB in size) at maximal possible compression,but when avast! comes to ISO image,whole thing simply dies. Everything starts locking and trashing on disk,its almost impossible to do anything on machine at that time.
While scanning all other archives i was able to use my system as usual,but not when i scan ISO image. And ISO images are not compressed at all,they are just containers.
Whats up with that?

[TeRanEX]

I have exactly the same problem...
Scanning zip, rar, bz2, tar, gz, 7z, whatever-files works fine but when avast scans an iso file it seems to generate a memory leak. I saw growing the memory usage of ashQuick.exe to over 300 megabytes resulting in system that does not react anymore (because it is swapping all the time?). It was only after i succesfully got the ashQuick.exe-process killed i could take control over the system again.
I noticed this with several iso-files. As an example the Ubuntu Live ISO
I'm using Windows XP SP1 (english) on a Intel Centrino (Acer Travelmate 4001)

[RejZoR]

Yeah i noticed the same with ashQuick,but this time it was On-Demand scan with Archives enabled. Unpacking engine is the same so results are also teh same.

[igor]

I just tried and didn't found anything wrong about it. The example given in the second post contains one big (400+MB) file - that will be copied to the TEMP folder during the extraction. Also, the whole file will be read (if avast! is set to scan the whole files), which may take a while - but I don't see anything different from e.g. RAR archive having the same content.

[RejZoR]

Well it was not ok on my machine. It's certanly far far from being weak.
It can scan 600MB RAR archive full of files without problems (i can do other things while its scanning). But when i scan ISO image same way as i did RAR archive,PC almost commits auto-suicide.
Memory usage goes skyrocket,CPU usage is enormous,disk is trashing like mad and scan takes ages (i usually cancel it since i can't wait that long for one simple ISO image).
I simply don't understand why so big difference between RAR and ISO scanning. RAR even uses high compression ratios which are memory and CPU intensive to decompress while ISO is just a container for files (like RAR archive with "Store compression"). So we don't need any decompressing power,just extract(copy to TEMP) and scan.

[igor]

You are right, it really doesn't do much more than extract the files to temp. Did you have problems with all ISO files, or just some of them? (i.e. how many iso images did you check?)
Was there anything special about them? (big number of files inside, big files inside... archives (such as installation CABs) inside... were they from various sources, or created all by one software?)