I can confirm that I've been seeing this as well. It does look to be
associated with Defender (as noted by the wdav-upgrade.zip file). The
file doesn't exist on the machine until Defender is installed then it
does its first update and this file shows...
This is what solved our issue of Big Sur machines not checking for
updates properly. I've even used this on Monterey machines that aren't
showing the latest Security Updates.
Would you be able to use the method outlined by "TalkingMoose" in this
thread to force the installation of the extension?
https://community.jamf.com/t5/jamf-pro/deploying-chrome-extensions-via-dmg/m-p/222298
This is the method I'm using to push out t...