High Proc utilisation when downloading microsoft wsusscan2.cab

Avast Free Antivirus / Premium Security
1

When I download wsusscan2.cab, needed for offline patching and the microsoft MBSA tool, Avast goes wild my CPU.
Background process: avast! Antivirus (32 bit) eats up complete core, hangs till I kill the download and reboot my station.

Specs:
Windows 10 x64 - patched till 14-11-2016
Dual core, 8Gb Ram.
Avast 12.3.2280 (B 12.3.3154.23)
Definitions 161116-0

Probleem starts when downloading; http://download.windowsupdate.com/microsoftupdate/v6/wsusscan/wsusscn2.cab
IE, Firefox and WSUSoffline all same issue. Download hangs, Avast eats up CPU time. Reboot needed before normal operations continue.

Workaround:
If I add the download (to) location and the URL (http://download.windowsupdate.com) to the exclusions in Avast, I am able to download the file normally.

2

Alternate procedure when downloading from a known and secure site is to simply disable the shields.
Since this update probably requires a restart, simply pause the shields till you reboot the system.

3

Hello bob,

Thanks for your post.
It’s not an update, its a cab with signatures and file info needed to check your Windows system patch state.
Diabling the shields does not solve the matter, it will still result in the same; a CPU hog.

I think it has got to do with the content or the size of the CAB (usually those are smaller).
Havent had time to get to use procmon or process explorer and dig into it…