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Consumer Products => Avast Free Antivirus / Premium Security (legacy Pro Antivirus, Internet Security, Premier) => Topic started by: realnabarl on June 05, 2010, 06:08:00 PM

Title: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: realnabarl on June 05, 2010, 06:08:00 PM
I just created a RAMDisk on my system by using Gavotte RAMDisk.
The type of RAMDisk I created is RAM Drive: http://tinypic.com/m/af8nsl/2

I find that files launched on it won't be checked by avast :-[
Some files what will be moved to quarantine on normal hard drive won't be alerted by avast! :o

Gavotte RAMDisk: http://www.multiupload.com/5W9VR1XQRL

Avast! 5 free version.

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One suggestion: disable some protections with one click.
Now we can only enable or disable ALL the protections by clicking the right menu of the tray icon.
But I don't want enable p2p and mail and webpage protection. Every time I need to disable them one by one in the main control panel.
Title: Re: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: DavidR on June 05, 2010, 06:17:29 PM
Well they aren't actually files on the RAM disk just loaded into memory and my assumption is that when you attempt to load them, the original file would be scanned before a copy is uploaded to RAM. However, I could well be wrong about that, you would have to monitor the avastUI, Real-time Shields, File System Shield to see what files are scanned at the time of loading them into the RAM Disk.
Title: Re: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: realnabarl on June 05, 2010, 07:05:17 PM
Well they aren't actually files on the RAM disk just loaded into memory and my assumption is that when you attempt to load them, the original file would be scanned before a copy is uploaded to RAM. However, I could well be wrong about that, you would have to monitor the avastUI, Real-time Shields, File System Shield to see what files are scanned at the time of loading them into the RAM Disk.
I put an exe file to [C:], and rename it again and again.
Recent scanned file shows avast! scanned it every time when I renaming it.
But when I did the same thing on [R:](RAMDisk), nothing was scanned.
Is this helpful?
Title: Re: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: DavidR on June 05, 2010, 07:44:44 PM
Well, yes and no, as avast has both a Persistent and Temporary cache.

Files that are scanned and digitally signed (and or) are white-listed have an entry in the persistent cache so that they aren't scanned again unless the file changes.

For other files that are scanned and show clear have an entry in the Temporary cache, so they aren't scanned multiple times if a) the file hasn't changed since the last scan or b) you reboot or c) a new virus definitions update is received.

The idea is to improve performance and cut down on unnecessary scans, so in certain cases if you scan the file a number of times or force it to be scanned, then it may be in one of the caches and it won't be scanned. It is very hard to determine if that is the case or not.

Simply changing a file name doesn't actually change the file, if you checked a files MD5 before and after renaming it, you will see they are identical and avast would see that also.
Title: Re: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: pk on June 05, 2010, 08:03:40 PM
realnabarl: there're some known problems between avast and Gavotte RAMDisk at Windows XP platform (do you use this OS, don't you?), see the last post: http://forum.avast.com/index.php?topic=53301.msg452161#msg452161.
Title: Re: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: realnabarl on June 05, 2010, 09:35:04 PM
Uh, yes, I'm using Windows XP SP2.
Title: Re: Avast! 5 doesn't check my files on RAMDisk and one suggestion
Post by: Asyn on June 05, 2010, 10:09:22 PM
Uh, yes, I'm using Windows XP SP2.

Update your XP to SP3 if you're on a 32bit system..!
asyn