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Avast will occasionally throw out a warning when Firefox checks for updates

ReindeerFloChilla
ReindeerFloChilla

For about the last month or so, sometimes when I check for Firefox updates through Help > About Firefox, Avast will tell me that a threat was blocked. Specifically, what comes up in the warning is:

Object: http://ww38.au4.mozilla.org/?force-1 | {gzip}

Infection: HTML:Iframe-inf

Process: C:\Program Files\Mozilla Firefox\firefox.exe


I've already run a scan with Avast and Malwarebytes, but both came back with nothing. I'm currently running the 64-bit version of Firefox, and I don't know if this issue exists with the 32-bit version, as I don't use it all that often.

Also, I've had to manually update the browser for the last year or so because Firefox never seems to find any updates. I don't know if this is related to my problem.

For about the last month or so, sometimes when I check for Firefox updates through Help > About Firefox, Avast will tell me that a threat was blocked. Specifically, what comes up in the warning is: Object: http://ww38.au4.mozilla.org/?force-1 | {gzip} Infection: HTML:Iframe-inf Process: C:\Program Files\Mozilla Firefox\firefox.exe I've already run a scan with Avast and Malwarebytes, but both came back with nothing. I'm currently running the 64-bit version of Firefox, and I don't know if this issue exists with the 32-bit version, as I don't use it all that often. Also, I've had to manually update the browser for the last year or so because Firefox never seems to find any updates. I don't know if this is related to my problem.

Chosen solution

Firefox would normally connect to https://aus5.mozilla.org (secure connection) to check for updates as you can see by the value of the app.update.url pref on the about:config page.

You can check if you have an app.update.url.override pref that is set to http://ww38.au4.mozilla.org

You can check if there is a user.js file in the profile folder.

You can use this button to go to the current Firefox profile folder:

Do a malware check with several malware scanning programs on the Windows computer.

Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

You can also do a check for a rootkit infection with TDSSKiller.

See also:

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All Replies (2)

cor-el
cor-el
  • Moderator

Chosen Solution

Firefox would normally connect to https://aus5.mozilla.org (secure connection) to check for updates as you can see by the value of the app.update.url pref on the about:config page.

You can check if you have an app.update.url.override pref that is set to http://ww38.au4.mozilla.org

You can check if there is a user.js file in the profile folder.

You can use this button to go to the current Firefox profile folder:

Do a malware check with several malware scanning programs on the Windows computer.

Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

You can also do a check for a rootkit infection with TDSSKiller.

See also:

ReindeerFloChilla
ReindeerFloChilla Question owner

I checked to see if there was an override set, and there was. Put everything back to default settings, and it seems fine. I'll keep an eye on the override preference and keep running malware checks to make sure it keeps. Thanks for the help!