Author Topic: Avast Free Antivirus - Two questions about scans  (Read 999 times)

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Offline Ferrara

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Avast Free Antivirus - Two questions about scans
« on: June 02, 2022, 06:46:49 PM »
Running Avast Free Antivirus on a Windows 10 Dell desktop.

1. After doing a manually launched smart scan, I get a notice that the next scheduled smart scan is in six days. How can I unschedule all scans? I don't want a scan suddenly running when I'm using my computer for music playback (when I close down all other apps so as to give full priority to the music software). I prefer to run regular scans when I choose to, and be able to have no automated or scheduled scans. I cannot find the setting anywhere to defeat or change when scheduled scans happen.

2. After doing a full scan I always get a bang icon and an info icon and when I click on the info it says "No threats found by full virus scan but we were unable to scan some files." This doesn't happen when I do a boot scan. Is there some setting I need to change to allow all files to be scanned during a full scan? Or is there a problem with certain files that they cannot be scanned, and if that is the case how can I find out which files aren't being scanned and fix it so they will be scanned? I have no exceptions implemented in my settings.

Offline Ferrara

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Re: Avast Free Antivirus - Two questions about scans
« Reply #1 on: June 02, 2022, 07:03:44 PM »
I found the answer to my first question under the Custom Scans page, and deleted the smart scan that was scheduled for the 8th of the month. So I trust scans won't be launching unless I launch them from now on.

So I only need to know about my second question.

Offline r@vast

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Re: Avast Free Antivirus - Two questions about scans
« Reply #2 on: June 03, 2022, 01:45:05 PM »
Hi,

Can you provide a screenshot, please?
Please see this article on how to generate a screenshot. https://support.avast.com/en-ww/article/Create-screenshot

Can you also enable reporting for Full Virus Scan (Menu>Settings>Protection>Virus scans>Full virus scans>tick Generate report file), then run a new scan and then send us a support package. https://support.avast.com/article/Submit-support-file

Offline Ferrara

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Re: Avast Free Antivirus - Two questions about scans
« Reply #3 on: June 03, 2022, 06:20:46 PM »
After my last full virus scan on 6/2/22 I changed the settings for full virus scan. These are what the settings look like now. Please tell me if I should change which boxes to tick. Screenshots attached.

Online DavidR

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Re: Avast Free Antivirus - Two questions about scans
« Reply #4 on: June 03, 2022, 08:12:24 PM »
These certainly aren't the default settings and could seriously slow your scan without any real benefit and you have also changed some of the Recommended settings.  You are also saying to Shut down computer after scan finishes, don't know why you would want to do that.

Also, I rarely if ever do any on-demand scans (including the Smart Scan), outside of related posts in the forums.

With a resident (on-access) scanner the need for on-demand scans is much depreciated. For the most part dormant/inert files are being scanned, the other active files are going to be scanned by the resident shields when they are activated.

Most Archive files by their nature are inert, so don't present an immediate risk, should you try to open an archive file, then it would be scanned by the resident protection, the File Shield.

The default settings are designed to give protection, without the scan taking a long time.
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Offline Ferrara

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Re: Avast Free Antivirus - Two questions about scans
« Reply #5 on: June 03, 2022, 09:13:23 PM »
These certainly aren't the default settings and could seriously slow your scan without any real benefit and you have also changed some of the Recommended settings.  You are also saying to Shut down computer after scan finishes, don't know why you would want to do that.

Also, I rarely if ever do any on-demand scans (including the Smart Scan), outside of related posts in the forums.

With a resident (on-access) scanner the need for on-demand scans is much depreciated. For the most part dormant/inert files are being scanned, the other active files are going to be scanned by the resident shields when they are activated.

Most Archive files by their nature are inert, so don't present an immediate risk, should you try to open an archive file, then it would be scanned by the resident protection, the File Shield.

The default settings are designed to give protection, without the scan taking a long time.

Please tell me how to restore the default settings for full scan and I will do that. Thanks. (I don't remember if I have any custom settings apart from Do Not Disturb mode, so I could reset all settings to default but I would rather just reset the full virus scan settings to the default settings before I changed them all yesterday).
« Last Edit: June 03, 2022, 09:42:28 PM by Ferrara »

Online DavidR

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Re: Avast Free Antivirus - Two questions about scans
« Reply #6 on: June 04, 2022, 12:07:17 AM »
Restoring default settings isn't something that can be done for one area in the the UI only has an option to restore defaults.

The easier option would be to restore the default settings and then apply your changes for Do Not Disturb.

Before making UI changes it is best to backup the settings to a file, that way they can easily be restored.

Your other option is based on the fact that on-demand scans are depreciated in a resident on-access antivirus, is not to run the scan. 

The choice of which is the lessor of two evils is yours.

EDIT: see attached image.
« Last Edit: June 04, 2022, 12:12:32 AM by DavidR »
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Offline Ferrara

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Re: Avast Free Antivirus - Two questions about scans
« Reply #7 on: June 04, 2022, 03:04:01 AM »
Hi,

Can you provide a screenshot, please?
Please see this article on how to generate a screenshot. https://support.avast.com/en-ww/article/Create-screenshot

Can you also enable reporting for Full Virus Scan (Menu>Settings>Protection>Virus scans>Full virus scans>tick Generate report file), then run a new scan and then send us a support package. https://support.avast.com/article/Submit-support-file

I have done as you instructed. You will see that in the first screenshot, scan history for full virus scans always show the "ghost with red bang" icon to the left and the information icon to the right, and when hovering mouse over the information icon one gets the popup "no threats found, but we were unable to scan some files". This does not appear to happen with the boot time scans. I just want to know what files cannot be scanned and why, and if I can correct this issue so that all files can be scanned in the full virus scan, as they apparently are scanned in the boot time scans. I don't really suspect that these files may harbor a virus, but I don't like seeing this error or warning message with a full virus scan.

Offline Ferrara

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Re: Avast Free Antivirus - Two questions about scans
« Reply #8 on: June 04, 2022, 03:06:51 AM »
Restoring default settings isn't something that can be done for one area in the the UI only has an option to restore defaults.

The easier option would be to restore the default settings and then apply your changes for Do Not Disturb.

Before making UI changes it is best to backup the settings to a file, that way they can easily be restored.

Your other option is based on the fact that on-demand scans are depreciated in a resident on-access antivirus, is not to run the scan. 

The choice of which is the lessor of two evils is yours.

EDIT: see attached image.

Thanks I did as you suggested, and restored default settings, then made my changes to the Do Not Disturb options, then saved a backup of the new settings.

Offline rocksteady

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Re: Avast Free Antivirus - Two questions about scans
« Reply #9 on: June 04, 2022, 10:53:31 AM »
The "Ghost icon" has been a subject of much confusion and concern in the past.
See this explaination from Avast dev: https://forum.avast.com/index.php?topic=237353.msg1558883#msg1558883

If no virus/malware threats are detected or reported from scans, as per your screenshot, then I would not be worried.

Ghost icon means some files cannot be tested. In the past we have seen this refer to OneDrive folders/files. I don't know if that is what is stopping Avast scanning some files for you. But as DavidR mentions, on-demand scans are less important than action of real-time detection shield.
« Last Edit: June 04, 2022, 10:55:24 AM by rocksteady »

Offline Ferrara

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Re: Avast Free Antivirus - Two questions about scans
« Reply #10 on: June 04, 2022, 04:50:43 PM »
The "Ghost icon" has been a subject of much confusion and concern in the past.
See this explaination from Avast dev: https://forum.avast.com/index.php?topic=237353.msg1558883#msg1558883

If no virus/malware threats are detected or reported from scans, as per your screenshot, then I would not be worried.

Ghost icon means some files cannot be tested. In the past we have seen this refer to OneDrive folders/files. I don't know if that is what is stopping Avast scanning some files for you. But as DavidR mentions, on-demand scans are less important than action of real-time detection shield.

Thanks for that link. I also got some reassuring info about the 'decompression bomb' I'd seen repeatedly in boot scans, which was a cause for concern.

I'm going to stop worrying about this and put the matter to bed. Thanks to all who replied to my thread, I appreciate the knowledgeable suggestions and explanations.

Online DavidR

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Re: Avast Free Antivirus - Two questions about scans
« Reply #11 on: June 04, 2022, 08:24:39 PM »
You're welcome.

Hopefully you won't be concerned in the future, even should you continue with on-demand scans :)
Windows 10 Home 64bit/ Acer Aspire F15/ Intel Core i5 7200U 2.5GHz, 8GB DDR4 memory, 256GB SSD, 1TB HDD/ avast! free 22.9.6034 (build 22.9.7554.734) UI 1.0.728/ Firefox, uBlock Origin, uMatrix/ MailWasher Pro/ Avast! Mobile Security