Unsecured threat detected

I am using AVG free anti-virus and the latest deep scan detected two unsecured threats relating to dyld_shared_cache which cannot be quarantined. I had a similar problem two years ago with dyld_shared_cache but then the threat name was MacOS:AdAgent and this turned out to be a false positive. Malwarebytes didn’t detect any problems when I ran it. I am including a screenshot of the new threats found.

I would be grateful for any assistance.

Thank you

Alastair