With the new version 31.0 of Firefox, the popular browser has added a new feature to security arsenal – now it will check all the downloaded files against Google Safe Browsing file reputation service to determine whether they are malicious or harmless. In order to do so, it calculates a SHA256 hash of all the downloaded files before completing the download, sends the checksum to Google Safe Browsing servers. If it gets a reply that the hash belongs to a known malicious file, then it does not complete the download, deletes the downloaded partial file and issues a warning. But if Google Safe Browsing replies that file is not one of matching malicious files in its database, then it complete the download.
This security feature is great if you do not have a good antivirus installed on your system. But if you already have a good antivirus software installed that checks for HTTPS stream and network for malicious files, then Firefox’s own anti-malware download check service is only going to slow down things without adding anything new to your computer’s protection. If you want to disable this new download check service in Firefox, then you can follow these simple steps:
- Open Firefox browser, type about:config in the address bar and press Enter.
- It will show you some warnings. Click on the “I’ll be careful. I promise” button to proceed. This will open a screen where all the Firefox configuration settings, their types and values will be displayed in form of a long list.
- Type safebrowsing in the search field to narrow down the configuration settings that we are interested in.
- Locate the setting named browser.safebrowsing.appRepURL, double-click on it and click OK to set its value to a blank string.
- That’s it. Now Firefox will not check downloaded files for being malicious through the Google Safe Browsing API.
Although disabling the Firefox’s new feature for checking all the downloaded files against Google’s malicious files database can make it a little faster, it may reduce the extra level of security that this feature is intended to provide. You should disable it only if you are using an excellent antivirus solution like avast! antivirus or ESET Nod32 antivirus.