Secure Connection Failed

Avast Free Antivirus / Premium Security
1

Acknowledgement: Before someone starts beating on me I acknowledge, in advance, that I am trying to understand an issue and not being deliberately obtuse or offensive.

I am using FireFox 39 running on Windows 10 10130.
I went to this website https://go.microsoft.com/fwlink/?LinkId=615187
and received the following message from FF.

Secure Connection Failed
An error occurred during a connection to go.microsoft.com. Peer’s certificate has an invalid signature. (Error code: sec_error_bad_signature)
The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem.

Then I tried the same line on IE 11 with no problem.

I poked around on the FF forum regarding this message and found several comments regarding TLS and SSL etc. In several of these topics someone asked if Avast! was being used.

So I went back to FF and disabled Avast! and then I could access the web site.

I then enabled Avast! and did a refresh on the website and found I could still access it.

If I restarted FF after enabling Avast! I could not access the web site.

I also did a restart on FF in safe mode (no addons) and left Avast! on and tried to go to the web site. No problems.

So I am totally confused as to whether or not this is even an issue or just how it works and where I should go next for some insight.

I accept the fact that somewhere along the line Avast! picked up a condition and flagged an error or caused FF to flag an error.

The thing I don’t understand is why I can access this web site through IE 11 whether or not Avast! is on or off.

This isn’t the only website I have had issues with but I picked this one as an example.

Any insight would be appreciated.

2

I just updated to Windows 10, and I’m now hitting this same issue in Firefox.


Secure Connection Failed

An error occurred during a connection to www.youtube.com. Peer's certificate has an invalid signature. (Error code: sec_error_bad_signature)

    The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
    Please contact the website owners to inform them of this problem.

The error message goes away, and I’m able to load the page after disabling Avast (or just HTTPS scanning). I’ve tried reinstalling Firefox & resetting my Firefox profile, but that doesn’t fix the issue.

It’s an Avast bug.

3

Same story. Current solution is to switch off the HTTPS scanning (Settings > Active Protection > Web Screen > Settings > Un-check “Scan HTTPS” check-box).
But that is not something I want to be, as un-checking scan for secure connection reduces anti-virus and web screen efficiency.

4

The Avast HTTPS scanner proxy is spoofing the SSL certificates in order to intercept, decode, and scan the encrypted HTTP data stream. Many secure web sites now strictly validate the SSL certificates and will fail if they detect any issues.

As suggested, turn Avast HTTPS scanning off until Avast finds a way to intercept the HTTP data stream after it is decoded.

5

just some info…

Explaining Avast’s HTTPS scanning feature https://blog.avast.com/2015/05/25/explaining-avasts-https-scanning-feature/

avast FAQ HTTPS https://www.avast.com/en-eu/faq.php?q=https