Author Topic: Very slow Full System Scan  (Read 44872 times)

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Offline BTIsaac

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Re: Very slow Full System Scan
« Reply #15 on: February 01, 2012, 08:24:38 PM »
Whilst you say you have change nothing else, avast's continually updates the avast signatures (and scanning engines) to improve detections one of those recent improvements is in the area of heuristics, with new more strict checks when heuristics are set to High. So this may be what you are experiencing.

And they decided to do that with picture files of all things? What? Did crackers finally found a way to hide self executing codes into them or something?

When I'm running a scan, I take no chances. I usually set every setting to maximum, with the exception of the "scan whole files" option, which I enable once every week or two. I sometimes reboot after encountering a suspicious file or visiting a site I don't trust 100%, to make sure I didn't pick up any dormant malware that avoid detection and self-execute during a system bootup. I don't know if viruses like that exist, but if they don't it's only a matter of time before a creative programmer will create one, and I'm the kind of person who likes to be prepared for a worst case scenario at all times.

Offline Pondus

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Re: Very slow Full System Scan
« Reply #16 on: February 01, 2012, 09:03:06 PM »
Quote
And they decided to do that with picture files of all things? What? Did crackers finally found a way to hide self executing codes into them or something?
what do you mean....are you saying picture files cant be infected?

Offline DavidR

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Re: Very slow Full System Scan
« Reply #17 on: February 01, 2012, 09:16:28 PM »
The problem is that it can be cyclic and may even rescan files already scanned. Typically some areas may have references back to files/locations on C:\, etc.
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Offline Lisandro

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Re: Very slow Full System Scan
« Reply #18 on: February 01, 2012, 09:23:17 PM »
The problem is that it can be cyclic and may even rescan files already scanned.
I think avast! detect this situation and avoid the double scanning (symbolic links).
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Offline BTIsaac

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Re: Very slow Full System Scan
« Reply #19 on: February 01, 2012, 11:02:26 PM »
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And they decided to do that with picture files of all things? What? Did crackers finally found a way to hide self executing codes into them or something?
what do you mean....are you saying picture files cant be infected?

If I were saying that, I wouldn't be so suspicious of everything I come across. I heard some experts say that since picture files are non-executable, even if they carry malicious code in the form of meta-data, said code can not be executed by opening the file. I learned only recently how shifty picture files can be. Photos I uploaded to DeviantArt have links advertizing my camera in the information section. I'm certain that malware from a previous, related infection can extract and execute that code, but that would imply that you are already infected.

By the way, I set Heuristics back to default and disabled PUP scan. No difference. A total full system scan takes roughly over a full hour to complete, and that's with Scan Whole Files disabled.

Offline Pondus

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Re: Very slow Full System Scan
« Reply #20 on: February 01, 2012, 11:24:05 PM »
http://www.mcafee.com/us/mcafee-labs/resources/threats-faq.aspx#6
Quote
6. Can JPEG, GIF, and other image files be infected?
Yes. Some software programs have vulnerabilities that contaminate JPEG files with malicious code. Contaminated JPEG files can carry or launch a virus, worm, or Trojan on unpatched systems.



Offline BTIsaac

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Re: Very slow Full System Scan
« Reply #21 on: February 01, 2012, 11:30:42 PM »
http://www.mcafee.com/us/mcafee-labs/resources/threats-faq.aspx#6
Quote
6. Can JPEG, GIF, and other image files be infected?
Yes. Some software programs have vulnerabilities that contaminate JPEG files with malicious code. Contaminated JPEG files can carry or launch a virus, worm, or Trojan on unpatched systems.

Sounds like Computer experts are as unreliable as ever. You ask the same question from two different sources, and they are bound to contradict each other.

Offline Pondus

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Re: Very slow Full System Scan
« Reply #22 on: February 01, 2012, 11:41:31 PM »
and microsoft released a fix in 2004 to protect

http://antivirus.about.com/od/securitytips/a/jpgflaw.htm

http://antivirus.about.com/od/virusdescriptions/a/perrun.htm


....cant seem find anything newer on this....yet



Offline MikeBCda

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Re: Very slow Full System Scan
« Reply #23 on: February 02, 2012, 12:18:31 AM »
While JPGs and other types of media files can theoretically become compromised, I keep separate folder-trees for my numerous JPG and MP3 files and exclude those folders (by path, not file-type) from full-disk scans which I find helps quite a bit.  I trust avast to catch any problems when individual such files are downloaded and/or opened.
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Offline BTIsaac

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Re: Very slow Full System Scan
« Reply #24 on: February 02, 2012, 12:50:53 AM »
Anyway... is there any word from the developers on the issue? The thought of having to deal with one hour scans for the rest of my system's life cycle, and perhaps beyond, is not a very pleasant one.

Ragamuffin

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Re: Very slow Full System Scan
« Reply #25 on: February 02, 2012, 01:36:25 AM »
It's still an issue in the latest release. Again, it began for me with the first of today's releases (120201-0) and only seems to really slow down on the files on my storage drive which are pretty much all pictures, music and videos, I haven't changed my settings at all recently and they're:

Heuristic Sensitivity - high
Use code emulation - checked
Scan for PUPs - Checked
Follow links during scan - checked
Test whole files - unchecked

I did a scan yesterday (1st Feb) at around 3am and it took 11.19 to scan 376GB, I did another just after the 120201-0 update and it took 50.20 to scan the same amount and had pretty much the same result with the latest 120201-1 update.

ady4um

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Re: Very slow Full System Scan
« Reply #26 on: February 02, 2012, 02:00:38 AM »
A few days ago the engine and definitions updates were corrected after several problems. The QA procedures were also improved, and avast 7 is in alpha development (soon to be beta). My guess is that the engine is under some tests and adjustments, and that the developers are focused on avast 7.

Just as the scanning speed got improvements during the last year (using engine updates), we will probably see improvements again. If not, then more users will notice it and ask about it.

We should be patient to see changes. When? I have no idea. These are all guesses. Until some new change is noticed, or some Avast Team member can reply with concrete info, there is no point on repeating our posts or assumptions. If they can (and if this is going to happen to "everyone"), they will improve it again.

LDThornton

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Re: Very slow Full System Scan
« Reply #27 on: February 02, 2012, 03:11:04 AM »
I, too, have noticed a major slowdown this evening when using full scan and default settings. It happens when avast scans MP3's. Whatever change was made today by avast was not a good one.

CahosRahneVeloza

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Re: Very slow Full System Scan
« Reply #28 on: February 02, 2012, 10:43:54 AM »
Still no news on this issue?

Now that more people are coming out & reporting this peculiar new behavior of Avast I hope we can now all accept the fact that the problem lies with the new changes with the program & we can stop putting blame on us users changing default settings as I highly doubt anyone would fiddle around with the AV on their own unsupervised.

No offense intended.
« Last Edit: February 02, 2012, 10:46:54 AM by CahosRahneVeloza »

kinfolk66

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Re: Very slow Full System Scan
« Reply #29 on: February 02, 2012, 02:32:58 PM »
I too am experiencing the same slow scan rates as the others. I have been using Avast Internet Security for almost two years now and have not been very happy with what seems as backwards progress the last few months. I may start looking for another security suite soon if these problems are not addressed soon. There have been more frequent flawed definition releases, the bad showing with AV Comparatives, and now this. :'(
 
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