When you have a file that looks suspicious, or you receive a link to an unknown PDF that may contain malware, it’s best to scan the file with a file virus checker. A virus scan can reveal if the file is tainted with viruses or worms, which can cause serious problems such as damaging or stealing data, or even using your computer to attack other systems.

Stay Vigilant: File Virus Checkers for Every User

You can do a free virus scan on any file, and if you’re on Windows, there is even a built-in basic antivirus scanner called Microsoft Defender. Alternatively, you can use online virus scanners such as VirusTotal, which can scan any file that you upload or drag and drop into the interface. The service is also incredibly easy to use, and it can be run on idle time, so it won’t take up any of your computer’s processing power while you’re working.

The way that virus scanners identify files as potentially malicious is through something called a hash, which is similar to a fingerprint. Every file has a unique hash value, and if a file is modified at all – even by one bit – the hash will change. A good quality virus scanner will check a file’s hash before analysing it, which can significantly speed up the scanning process.

Once the virus scanner has analysed a file, you’ll see a list of all the engines that used it, along with a safe-o-meter and more details such as the product and company name, version numbers, original file name and more. This makes it easy to see if you should be wary of the file or not, but you can also test the file in a sandbox environment if you want to be doubly sure that it’s safe.