Malware spreads through many channels – infects USB disks, infected email messages, drive-by-downloads, infected websites and so on. When you download files from the Internet, some of them could be infected with malware. Usually your installed antivirus takes care of any suspicious or infected files, but if your antivirus product does not come with a web scanner or HTTP scanner module, then you are not properly shielded from malicious downloads. You can boost your online security by using the Fireclam extension for Firefox which scans all the downloaded files using the Clam free antivirus. The Clam free antivirus can work along with other security products so Fireclam works even if you have any other standard antivirus installed on your system.
Before you can use the Fireclam extension, you have to have the ClamWin antivirus (Clam antivirus for Windows) installed in Windows. On Linux, you can install Clam antivirus using the sudo apt-get install clamav clamtk command. After you have installed Clam antivirus and updated the definitions database, you can proceed further.
The Fireclam extension can be installed from the Mozilla Firefox plugins repository. The extension is not written keeping the Windows users in mind. So it does not work straight out of the box. You have to modify its configuration before it can work. You can open the Fireclam options from the about:addons page. In the options, you have to browse and select the clamscan.exe file which is located in the ClamWin antivirus installation path. Also you have to select the folder where the main.cvd database file located in the ClamWin antivirus installation folder.
Now when you download any files from the internet, Fireclam will invoke the Clam antivirus to scan the downloaded files through the command line interface. In Windows, you may see a little command line interface window for a second. If a malicious file is found, Fireclam shows you the result. But takes no action, you have to delete the malicious file yourself.
Conclusion: The Fireclam extension for Firefox can help you scan all the downloaded files using the free Clam antivirus. It works both in Windows and Linux. Since Clam antivirus can work along with other security products, it can work even when you have other antivirus products installed.
You can download Fireclam extension for Firefox from https://addons.mozilla.org/en-US/firefox/addon/fireclam/ and ClamWin free antivirus for Windows from http://www.clamwin.com/.