Table of Contents
Everyone regularly downloads files or apps from the Internet, whether it’s to study, grab images, or find tools to work more efficiently. Unknown files can be risky because they can hide viruses designed to steal data, extort money, or abuse your PC.
Fortunately, using one of the best antivirus software can help protect against these threats. There are also many good free options available, as you’ll see in our roundup of the best free antivirus programs.
If you only need to scan one file, there are other methods available, as even the best antivirus can benefit from a second opinion when dealing with particularly suspicious files.
How to run a virus scan
If you’re unsure about a file from a sketchy site or suspicious email, start with a virus scan. Sites like Virustotal allow you to upload and scan files using over 70 virus scanners, providing a thorough and easy way to check security.
Adrian Sobolewski-Kiwerski / Foundry
The site allows you to upload various file types, such as .exe files, PDFs, videos and images, for analysis against more than 70 virus databases. These effectively detect threats such as viruses and Trojan horses, which are common attack methods. Virustotal uses well-known scanners such as Bitdefender, Kaspersky, Avast and more, providing thorough checks without affecting the performance of your PC. It has been owned by Google since 2012 and is a trusted site.
It’s best for scanning individual files, and large files can take some time. For a full system scan, it is much better to just use regular antivirus software. Please also note that the results of your submission will be shared in the app to make further improvements. That’s something to keep in mind when submitting potentially sensitive files.

Adrian Sobolewski-Kiwerski / Foundry
To use it, simply click on the Choose File option and upload the file you want to scan. You should get your results within seconds.
Once you scan a file, you can see how many of the search engines detected a problem. A ‘safe-o-meter’ quickly measures whether a file is safe, and you can also click on the tabs to view detailed information such as the product and company name, version numbers, original file name and much more. you probably need.
For regular files, such as executable files (.exe files), you will most likely see a pop-up telling you that the file has already been analyzed recently. You can click the ‘View last analysis’ button or – if the most recent date was months ago – click Reanalyze to check it again.
How to quickly check if a file is safe with Microsoft Defender
For Windows users, Microsoft Defender offers a simpler solution. This built-in antivirus offers real-time protection and can quickly scan files.
Of course, the search won’t be as extensive as that with Virustotal, but it’s a quick way to discover the more obvious threats. It is also very convenient, always just a few clicks away.

Adrian Sobolewski-Kiwerski / Foundry
The first step to using Windows Defender’s file scanning option is to find the file itself.
Open File Explorer (you’ll find it in the Windows Start menu) and navigate to the location where it is saved. This is usually the Downloads folder, one of the folders on the left side of File Explorer.
Once there, locate the specific file. If necessary, you can also scan the entire folder. For a single file, right-click on it.

Adrian Sobolewski-Kiwerski / Foundry
Once you right-click on the file you want to scan, you’ll need to expand the short list of options in the pop-up menu. To do this, click on the Show more options bar – it should be at the very bottom.
Click Scan with Microsoft Defender

Adrian Sobolewski-Kiwerski / Foundry
Once you click on Show more options, you will be greeted with another pop-up list menu. Here you will want to find the Scan with Microsoft Defender option. This should be right next to a blue shield icon. Once you find it, simply click on it.
Your scan is complete

Adrian Sobolewski-Kiwerski / Foundry
After waiting a second or two, a new window should open with Microsoft Defender. There you will see your scan results or if the file you are scanning is slightly larger, you will see the progress of the scan.
That’s it: your file has been completely scanned and you can see if it contains any malicious software. You may also want to know how to check if a link is safe.