Thank you for reporting the issue.
Could you please help us with investigation by providing some data?
Please enable Avast debug logging (Menu -> Settings -> General -> Troubleshooting -> Enable debug logging).
Reproduce the issue:
Enable HTTPS scanning in the Avast Web Shield setting again and try visiting sites so that more certificates are generated - you can take a look into the 'avast! SSL Scanner Cache' group in MMC and check the 'Issued to' column.
Create a support package (
https://support.avast.com/en-eu/article/Submit-support-file) and post the ID here.
It would also be useful if we could take a look at which certificates were generated (even before debug logging was enabled).
Please go to MMC -> 'avast! SSL Scanner Cache' -> right click 'Certificates' and select 'Export List...' to export the certificate list as a text file.
You can send the list by e-mail as there is no automated feature for this. Feel free to remove any certificates that you consider personal from the list.
It might be a bug - we will be able to give you more information when the issue is investigated.
The certificates should be deleted if they are older than 30 days, or if it is confirmed to be a bug, a fix might be released.
Other than that you can safely delete any certificate issued by by Avast Web/Mail Shield Root (their expiration date should be in only a couple of months).
Thank you very much,
Jakub