Malware not Detected by Avast on Extraction

Avast Free Antivirus / Premium Security
1

My Avast Free 9 has default setting

I got a folder which contains a malware which is detected by Avast database

But Avast does not catch the malware on Folder extraction (using 7zip)

scanning the extracted folder,Avast will detect it

Why is that happenning?!!!

2

Maybe the file is not being accessed. Do you have PUP detection on for rea time scanning, its disabled by default.

Have you scanned the folder via context menu or via interface?

3

also asked here. http://forum.avast.com/index.php?topic=136637

4

Thanks Pondus
I got my answer

5

Although this feature makes Avast lighter but I think it is not a good idea.

I can copy/paste the “malware containing” folder without Avast interfering.

I can copy the folder to a Flash Drive…and the malware can spread to another computer (someone may execute the malware on unprotected system believing it is safe because it has passed Avast)