Over the last few days I’ve noticed that whilst browsing the internet, clicking the padlock icon in the browser shown against any HTTPS site now says “Verified by: avast! Web/Mail Shield”, rather than the certificate issuer as it used to.
OS: Windows 10 Home (64-bit)
Browser: Firefox 59.0.2 (64-bit)
I’m not sure if it is the Web/Mail shield is acting as an intermediary so that the email can be scanned before it is either saved to your email client or to your web browser.
That said, I rarely use WebMail, I haven’t bumped into this, but testing this in Firefox 52.7.3 ESR version, Avast Free 18.2.2328 and my Gmail it is reporting Google Trust Services as the Verified By info.
I’m using Avast Premier 18.2.2328. I’ve never touched the Web/Mail Shield component. It does come as slight concern though as you’d of course expect to see the accurate info in terms of certificate here. Screenshot attached.
Are you using the Avast Security Browser Extension ?
I haven’t got the AOS Firefox add-on installed and given its description might see it acting as a conduit, which would probably need it to have its security certificate associated to the page.