Chrome: “You are using an unsupported environment variable: SSLKEYLOGFILE”

With Avast or AVG antivirus installed, latest Chrome Canary now shows an info bar on startup with the message”you are using an unsupported environment variable: SSLKEYLOGFILE. Stability and security will suffer.”

We always surprised why Google Chrome hasn’t had any issues with Avast in the past or present, which users greatly experience with every major Firefox release. For instance, we can say Avast breaking HTTPS websites in browser and AVG  deleting saved passwords and logins. Now Chromium team started detecting bad actors or antivirus software that try to intercept HTTPS traffic by injecting environment variables into Chrome browser.

According to bug created here, we learned that a user can log the plaintext of their own TSL traffic by creating “SSLKEYLOGFILE” environment variable.

Chromium team wants users to aware of this variable set in the Chrome browser. Apparently, the team expresses concern this variable has already been used by bad actors and thus, added SSL key log file to bad flags.

If you’ve Avast installed, you should know the antivirus sets SSLKEYLOGFILE in the Chrome process but not in the system environment variables.

You can verify this on your system by doing this:

1. Open System Properties dialog,

2. Click on Advanced tab, and further click on “Environment Variables”

3. And look in “User Variables”.

Process Explorer indeed reveals Avast has done that as you can notice SSLKEYLOGFILE in Environment tab of Chrome.exe process properties in the screenshot embedded below.

At the moment, the info bar will appear on every startup of Chrome Canary, disabling HTTPS Scanning or Web Shield in Avast hasn’t removed the message. If you want to use Chrome Canary with Avast, live with that message or let us know if found a way to get rid of it.