I’m running Avast! Free Antivirus on Windows XP, old Pentium 4, XP 32 bit OS. I’ve been doing Avast! upgrades pretty regularly within a few days of the announcement popup stating that there’s a new version available. I’m now at ver 6.0.1203.
Starting not with this version, but I think the one before it (6.0.0x ?) that I had to download and install a few weeks ago, I noticed that all manual scans are now finished instantaneously. It seems way too fast. That is, when I am in explorer and right-click one or several files and choose “Scan filename.xxx”, Avast! comes up and almost immediately states, Scan Complete, NO THREAT FOUND. No matter how big the file is. Even some that are near 1 GB in size.
In earlier versions, it would scan the file(s) and show the progress, the amount of data tested, etc, and it would take several seconds. Now it looks like it isn’t even doing anything. Doesn’t matter if it’s a file I just downloaded or one I’ve had for a long time. Same result. When it does a scheduled full scan, it takes roughly the same amount of time it used to, though. About an hour and a half for all three hard drives. So it looks like only manual (per file) scans are affected.
What’s going on here? Did the program code get changed somehow recently so that it doesn’t have to fully scan each file anymore if it had already scanned it in the past? That still wouldn’t explain why a file I just downloaded also is instantaneous when I manually scan it. Unless it auto-scans it as soon as it’s fully downloaded, or something like that.
It’s a little unnerving. Looks like the manual scans aren’t doing anything at all, yet reporting “no infection found” anyway. Thanks for any info that contributors or Avast! developers may have on this.
Well, it’s fast but it really depends on what you were scanning. Scanning few giabytes of video files will take nearly no time to complete. Where scanning few hundred DLL files will take a while.
Does a full system scan also end instantaneously or does it take a while to complete?
A full system scan takes quite a while, pretty much just like it used to. But any scans done on individual files (through Windows Explorer, locating the file and then right-clicking and choosing Scan) are instantaneously completed. Doesn’t matter what kind of file(s), or how big. It’s very different from how it used to be several weeks ago.
Try scanning some big program using context menu option. If it finishes instantly there is something wrong. Also does the file scan count increase or not? I remember there was a problem with explorer context scan before but it was fixed. Could be a similar thing.
Wow, I can’t believe I found such a relatively recent thread on this subject.
I’ve noticed the exact same thing on my sys. lately.
Is there any new info or other threads elsewhere on this issue–b/c I agree that it seems something must be amiss in light of how long the scans used to take and the almost instantaneous scans now.
Thanks for any help.
Toshiba NB505
Windows 7 Home Premium
32 bit OS
Intel Atom CPU N455
RAM 1.00 Gig.
No, there is nothing wrong - the scan of a file, especially huge files like movies, does not depend on the size, so scanning a 1GB file takes the same time as scanning a 1MB file (i.e. almost instantaneous).
i noticed this the other day, question is, is avast still scanning the WHOLE file for malware, as it’s been instructed to do in the settings?
or is it just doing a basic check of part of the file?
this would make manual scanning all but useless
also when did avast make this change to the right-click manual scanner?
There is no point in checking the whole movie file for malware - as the malware cannot be hiding “in the middle”.
So, for known file types, only the relevant parts of the files (those that can be affected by malware) are scanned - scanning anything else would be useless.
It’s got nothing to do with the right-click scan specifically, it’s a property of the scanning engine (and the areas to scan are “dynamic” - meaning that if a malware appears tomorrow which would be hiding somewhere else and the corresponding detection is added, avast! starts to scan that “somewhere else” at the same time).