Author Topic: Deep Scans Failing With "failed scan: failed files limit exceeded"  (Read 818 times)

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Offline danj_mac

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This seems to be a recent development as a previous Deep Scan a month ago did not trigger this error.
Avast Security 15.3 (2a902fb2b965) Definitions: 22080322
Scan Settings: Notify of PUP, Scan Archives, Test Whole Files

While doing a Deep Scan of my system, I noticed that the scan finished surprisingly quickly and that it did not scan as many files as it did on the previous run.
The results screen did not provide any useful information, only "Scan Failed". I was able to locate the full scan log using Console.app in /Library/Logs/Avast/scan_helper.log.
This revealed that a whole bunch of Windows-like files were failing as unscannable.

Here is a sample:

2022-08-03 12:41:48.118-0400 [38868: aa158] NOTICE  scanner: error occurred while in fallback mode 2; reporting /Users/<REDACTED>/.pyenv/versions/2.7.18/lib/python2.7/site-packages/pip/_vendor/distlib/t32.exe as unscannable
2022-08-03 12:41:49.119-0400 [38868: aa158] WARNING scanner: failed to send data to client
2022-08-03 12:41:58.961-0400 [38868: aa158] WARNING scanner: error on client connection 0
2022-08-03 12:41:58.961-0400 [38868: aa158] ...     scanner: connection closed on message boundary


This is not specific to Python binaries or 32-bit binaries. It also fails to scan .dlls and other .exes. The largest source of these is my steamapps folder which contains a bunch of Unity/Mono-based games. There are also some node_modules that I expect as well. None of the entries I found in scan_helper.log seem to be unexpected (I am a developer), but after a certain number -- I cannot tell how many, and/or it varies -- the scan gives up. It reports "No Threats Found" but says "Scan Failed".

This is frustrating for a number of reasons:
- First, I cannot complete a whole scan, and I cannot pick up where I left off, so I don't know how much was scanned or how to do it piecemeal.
- Second, there is no indication from the UI of what the actual problem is. Only getting "Scan Failed" but seeing "No Threats Detected" is confusing and doesn't really leave you understanding what you're protection status really is. (Luckily being a dev, I went trolling through Console.app to see if there was any useful info, and thankfully there was.)

Unfortunately I do not know what version of the Avast I was using when the scan was working properly. All I know is that I last did a Deep Scan about a month ago (so first week of July 2022).

Any ideas what may be wrong or if there is a fix in the works from the Avast team?
I have not yet tried to uninstall and reinstall the application, but that will be my next step if I can't get any full scan done, even of my /Users/<me> dir.

Edit: M1 macOS Monterey 12.5 (21G72)
« Last Edit: August 03, 2022, 07:02:50 PM by danj_mac »

Offline masterryan

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Re: Deep Scans Failing With "failed scan: failed files limit exceeded"
« Reply #1 on: August 04, 2022, 02:46:31 AM »
I too, have a similar issue where Avast takes abnormally long scanning python scripts (even though they are small in terms of file size). Stuck around 3% even after 50 minutes of scanning before I cancelled it (yesterday). Hopefully the Avast Team can look into it and fix the virus definitions.

Avast Mac Security 15.3 with definitions updated to 4 Aug 12am UTC (not able to find the version number). Looks like python and go Windows binaries installed on Mac (mingw) have some issues being scanned on the latest version and virus definitions installed. (didn't get past these to scan mono binaries)


2022-08-03 21:26:26.262 [34368:12039a] NOTICE  scanner: error occured while in fallback mode 2; reporting /usr/local/go/src/debug/pe/testdata/gcc-386-mingw-no-symbols-exec as unscannable
2022-08-03 21:26:27.292 [34368:12039a] WARNING scanner: failed to send data to client
2022-08-03 21:26:40.482 [34368:12039a] WARNING scanner: error on client connection 0
2022-08-03 21:26:40.482 [34368:12039a] ...     scanner: connection closed on message boundary
2022-08-03 21:26:40.483 [34368:12039a] NOTICE  scanner: error occured while in fallback mode 2; reporting /usr/local/go/src/debug/pe/testdata/gcc-amd64-mingw-exec as unscannable




I did a full scan last month (on 15 July) and it took an abnormally long (2h 42 min) compared to the usual average of around 1h 30min. Not sure if this helps.


Offline ondrej.kolacek

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Re: Deep Scans Failing With "failed scan: failed files limit exceeded"
« Reply #2 on: August 05, 2022, 10:10:10 AM »
Hello,
regarding danj_mac: I was told that your version of Definitions had an issue that should have been fixed by an update from 3.8.2022 ~19:00 GMT ; to be 100% sure it is fixed I would suggest manually updating Avast AV from the menu. Hopefully that should help.
Regarding masterryan: Please send us support package mentioning this forum post in description (https://support.avast.com/en-ww/article/Submit-Mac-Security-support-file), I can check what could be wrong.
Kind regards,
Ondrej Kolacek

Offline danj_mac

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Re: Deep Scans Failing With "failed scan: failed files limit exceeded"
« Reply #3 on: August 09, 2022, 08:34:05 PM »
Quote
manually updating Avast AV from the menu
Thanks! This did the trick.