If you want to download a file, but you are not 100% sure that this file is safe for the security of your computer, you can check that it is secure without downloading it. Your antivirus, even if it is very good, might not detect a hidden virus.
But rest assured, there is a solution to ensure that a file is secure before you even download it. You will be able to scan this file for malware using 60 antiviruses grouped into a single free online tool: VirusTotal.
This online tool is not an alternative to basic Internet safety practices. (we don't do just anything and we don't hang around on just any site ;)), but it's a way of doing an advanced check on a file that might seem dubious to you.
Use VirusTotal to check files online
To use this service, you will first need to locate the download link of the file you want to check. We are talking here about the direct link to download the file and not the address of the page where the link to download it is located.
For example, if you want to download software (an executable) this link should end in .exe (or possibly .zip if the file is compressed), if it is a document it will end in .doc for Word, .pdf for a PDF… By hovering over the link, it should appear at the bottom of your browser.
You can usually retrieve this link by right-clicking on the link and clicking "Copy link address" (Chrome and Firefox), "Copy shortcut" (Internet Explorer)...
Then go to the site VirusTotal. This tool has been owned by Google since 2012… so you can go with confidence.
On the page that opens, click on the "URL" tab and copy your link into the box. Click on the small magnifying glass on the right ("Search or scan") or press Enter to scan the file.
VirusTotal will then upload your file to its servers and scan it with a range of antiviruses.
If you see the message "No engines detected this URL", this means that the file does not present any known risk.
The "0/65" displayed below means that none of the 65 antiviruses have identified the file as malicious. Therefore, there is a good chance that it is virus-free. Of course, it is difficult to guarantee 100% the security of a file, because it is always possible that a new virus, not yet referenced by the antivirus databases, is hidden there... so in any case, favor trusted sites for your downloads.
In the event that your file is suspected by one or more antiviruses, the tool will indicate the number of scans that detect an anomaly.
In some cases, the result will be unanimous, but in others it may be that only a few antiviruses detect a problem with the file. In these cases, we may be dealing with a false positive or it is because these antiviruses have detected a new threat before the others. It is then possible to access community comments about this file.
In the case of the example below, this is a test file set up by VirusTotal… and this is what is coming back from the community comments.
Integrate VirusTotal into your browser
To facilitate this download verification process, VirusTotal hasextensions for your browser. So, when you right-click on a download link, you will be able to use the “Check with VirusTotal” option to verify the security of the link… without having to copy and paste the link on the VirusTotal site.
The extension is available for Chrome, Firefox et Internet Explorer.
Ultimately, if VirusTotal is unanimous about a file's dangerousness, you should avoid it. If the results are mixed, you should remain cautious, but don't hesitate to try to glean more information to understand why this file is potentially dangerous.
If this file does not present any anomaly, it means that it is not detected by antiviruses as being a malicious file. But that doesn't mean it's safe! Antiviruses are not perfect, far from it! Make sure you download your files from trustworthy sites!
