The internet is now full of frauds and hijackers. Hackers are continuously using every single trick to break into online accounts and computers. To achieve such purposes, malware, trojans are common method used by attackers. And you may already know that public download websites are the main place to host malware and viruses.
Whenever you are downloading any file from any untrusted source or where people can upload files easily to make it publicly available, it’s a big chance that you could infect your PC with a kind of malware, say it virus, trojan or keylogger. So when you are using public download hubs, you need to take extra level of caution. You may think that your own anti-virus software will take care of the rest after you download the file. But you can also check for virus before downloading the file. Another important fact is no antivirus is perfect. While some antivirus programs may detect virus in an executable, others may not. Chrome, Firefox, Opera comes with in-house safe browsing feature where the browser will try to analyze linka and files against possible malware or infection. But it’s not enough.
Here I will show you how you can scan any file with multiple antivirus engines before you download on browser. This also includes URLs/web pages. Before we proceed, you need to know that there are some services that let us scan files with multiple antivirus scanners online for free. Among them, VirusTotal is mostly popular and widely used. VirusTotal also comes with desktop, browser and Android tools. We will use VirusTotal’s browser tool to scan files online for malware prior to download.
Note: Some antivirus applications that you install on your PC will add a browsers extension that lets you scan URLs and files on browsers. But using VirusTotal will let you scan with more than one antivirus scanner. So you can make sure if your files have malware or not.
Scan Files on Browser before Downloading (Firefox)
VirusTotal has a very simple add-on for Firefox named VTzilla.
1. Install it on your Firefox using the install button on VTzilla page.
2. Restart the Firefox to activate the add-on. Now whenever you try to download a file within Firefox, you will have an option to scan the file with VirusTotal. For example, I will try downloading the program USB File Unhider, a tool developed by me. Click Scan with VirusTotal in Save File dialogue.
3. Clicking on ‘Scan with VirusTotal’ will bring you to VirusTotal’s URL scanner page where it will only scan the URL. To scan the file, click Downloaded File Analysis under File Scan section.
4. Now VirusTotal will scan the actual file that you were trying to download.
This is how you can scan files with multiple antivirus scanners before downloading to your computer.
VTzilla also adds a VirusTotal toolbar on Firefox. You can use this tool to search for file hashes (md5, sha1 and sha256), URLs. To scan current site you are visiting, use Scan current site.
Note: If you don’t want this extra VirusTotal toolbar, you can simply disable it by right clicking on the toolbar and removing tick mark from VirusTotal toolbar.
You can still continue to use file scanner.
Scan Files Prior to Download (Chrome)
Note: VirusTotal extension for Chrome doesn’t come with the feature where it can ask you to scan the file in ‘Save file’ window. Rather you need to scan the hosted URL from where the file can be directly downloaded.
VirusTotal extension for Chrome is named VTchromizer. Here’s how you can use it.
1. Install VTchromizer for Chrome from Chrome Web Store.
2. Whenever you are about to download a file by clicking on a direct link that hosts the file, right-click on the file link and choose Check with VirusTotal.
3. Like Firefox, it will send you to the URL scanner page.
5. As previously done, click Downloaded file analysis.
6. You will be presented with files scan results against viruses.
Other Browsers (Opera, Safari, Internet Explorer, etc)
VirusTotal extension isn’t available for all browsers. But you can still scan files before download.
1. Copy the direct link to the File from right-click context menu on your browser.
2. Go to virustotal.com and choose URL tab. Paste the link and hit Scan it.
3. Now as before, click downloaded file analysis to see actual file scan results.
Scan a File that you already Downloaded
If you already downloaded a file and want to scan it further, you can scan the file with multiple antivirus engines.