Sophos XG labelling encrypted uploads and unscannable malware downloads?

[Garacesh]

We have some information to send off to the NHS about certain pupils and obviously this should be sent encrypted. However, when in GMail (browser version), all encrypted attachments (password protected .zip file, created with 7Zip, if it matters) fail to upload. Tested in both the latest Chrome and Edge.

 

I've been digging around and I've narrowed this down to the problem is definitely caused by the web filter.

If I check the log viewer I can see that Sophos is tagging it as Malware because it can't scan it (Protocol: HTTPS, Detection: Unscannable, Log subtype: Virus, Message: Malware 'Unscannable' was detected and blocked in a download from mail.google.com, Message ID: 08001)

 

About the only Malware settings I can find in Sophos are under Configure / System services / Malware protection, and the only option there is to set what my 'Primary antivirus engine' is.

 

I don't really want to start blanket not-inspecting traffic to GMail for certain members of staff if I can help it, but I'm not sure what other options I have at the moment. I guess it's not the worst thing in the world, we still have local AV, AppLocker, and FSRM blocking certain filetypes being saved to user-writeable areas, but still..

 

Anybody dealt with this before?

Edited September 21, 2021 by Garacesh