How to Check a File for Viruses

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Knowing how to check a file for viruses is critical if you suspect you’ve downloaded a suspicious program and are worried about a potential malware infection. Making the wrong decision could give hackers complete control over your device and put you at risk of identity theft and fraud – so it’s important to know that you’re safe.

Fortunately, there are some simple ways to check a file for viruses using antivirus software or an online checker. In this guide, I’ll explore how to scan a download for viruses both on your device and online and how to enhance your digital security going forward, based on my experience in the cybersecurity sector.

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Best Antivirus Software to Scan Files for Viruses

  1. TotalAV – Overall Best Antivirus for Scanning Infected Files
  2. Bitdefender – Fastest Antivirus for Scanning Files
  3. Norton – Best Family PC Antivirus for Scanning Files

How to Check a File for Viruses

  1. Get a high-quality antivirus. TotalAV is my recommendation, thanks to its 100% virus detection rates during my testing, and its excellent security features.
  2. Install the software on your PC and open it.
  3. Go to Custom Scan, select the file you’re concerned about, and run a scan.
  4. Quarantine or delete the file if the TotalAV scan detects a virus.

How to Avoid Virus-Infected Files

There are many situations when you should check if a file is safe before you download or open it. Maybe a friend or colleague has sent you an attachment, but you’re not sure where it originally came from or if it’s safe. Alternatively, you might want to scan a file from an unfamiliar website before downloading it to your device.

You should be particularly wary of .exe files as they can install programs on your device. The number of infected Microsoft Office files that have been documented has dramatically increased in recent years, though, and PDF and .docx files are by no means guaranteed to be safe.

What’s more, the number of never-previously-seen malware variants is increasing every year. Worry not, though. I’ll provide a detailed step-by-step guide on how to scan for viruses before downloading a file, both on your computer and online, based on my extensive experience in testing and researching the best security tools on the market.

How to Scan Files for Viruses on Windows with Antivirus Software

TotalAV is one of the best antivirus programs around and makes file scanning easy. It offers real-time protection – continuously monitoring system processes and app behavior for anomalies – and can scan files for viruses before downloading completes to stop malware from reaching your system.

In addition, its WebShield feature scans links and will alert you if they point to malicious sites or URLs, effectively allowing you to scan files before downloading them.

You can also manually scan files on your device to check them for viruses. Here are step-by-step instructions on how to scan downloads for viruses:

  1. Open TotalAV

    If you don’t have an account, go to TotalAV’s website, pick a subscription, and download the software to your device. When that’s complete, launch the TotalAV app.

    TotalAV smart scan results

  2. Go to Custom Scans

    In the main window, click on the Shield icon in the left menu and then Malware Scan. Next, in the Malware Scan pane, click on Custom Scan in the bottom right.

    TotalAV Custom Scan option

  3. Choose the Files or Folders to Scan

    From the Custom Scan Options page, you can choose to scan a specific file or folder.

    TotalAV Custom Scan screen

  4. Results Summary

    Once the scan has finished, you’ll get a Results Summary page with detailed information on the scan results. You can choose to quarantine, delete, or whitelist the flagged files as needed. You just need to click Take Selected Actions to complete the process.

    You can dismiss the results if you want to ignore TotalAV’s recommended actions and are confident that it’s flagged legitimate files, and you can check back on quarantined files at a later date if needed. The file virus scan is now complete.

    TotalAV antivirus smart scan

    You can also run a virus check on a folder with TotalAV. The process for how to check a file for viruses with Bitdefender, Norton, and McAfee is very similar.

TotalAV and Bitdefender are both great options if you need to scan a file for viruses on Windows 11. They can both also run comprehensive system scans and quick scans.

Unlike tools such as Microsoft Defender, they come with additional features to provide multi-layered security and protect against ransomware and phishing attacks.

Check out our guide to the best antivirus software for more details on these providers and other file scanners, which is based on our testing of 15+ leading antiviruses, among other cybersecurity solutions.

How to Scan a File for Viruses Online

VirusTotal is a free online service that enables you to scan a file for virus indicators. The tool uses multiple antivirus databases from different security vendors. You can also scan links, so you can scan a file for viruses before downloading it.

It’s a good file checker for virus scans, but keep in mind that you shouldn’t upload files containing personal or sensitive information and that a product like TotalAV will be a better solution in most cases. Here are all the steps you need to take to upload and scan a file:

  1. Go to VirusTotal and Pick a File

    Go to the VirusTotal website and upload your file. Click Choose file and select the relevant file on your computer, or drag and drop it into your browser window as a first step for how to check a file for viruses online.

    <strong>Go to VirusTotal and Pick a File</strong>
  2. Scan

    VirusTotal will then scan the file using the latest virus data from multiple antivirus providers.

  3. Threat Detected or All Clear

    If the service detects a threat, it’ll let you know that one or more security vendors have flagged the file as being potentially malicious.

    VirusTotal will also let you know if no threat is detected. The file is likely safe, and you don’t need to do anything further. You now know how to check if a file has a virus before downloading it using an online file virus scanner.

    If you’ve downloaded a malicious file, you should use antivirus software on your computer to quarantine or remove it. TotalAV is a robust solution for comprehensive protection and can check virus signatures against every file on your device to ensure you’re safe.

What Can Virus Scans Find? What Viruses are Most Often Hidden in Files?

Virus scans can find malware and infected files on your system – and I’ll now explore just what a file virus checker can find. Some common types of malware and viruses include:

Worms

Worms infect a system, replicate themselves, and spread via computer networks, contact books, and phishing emails. These viruses can spread widely and are often disguised as benign files.

To protect yourself, ensure you never open attachments on suspicious emails. Ideally, you should also avoid opening messages and emails from unknown individuals.

Trojans

Trojans are a type of disguised malware program that appears to be safe but gives hackers access to your system and files. In some cases, the hackers may hide or alter the original file name to escape detection.

Spyware

Spyware tools allow third parties to track activity on your device or to control the device itself. This puts you at great risk and exposes you to identity theft and fraud.

Keyloggers are an example of spyware and allow hackers to track all your keystrokes, including your passwords, logins, and account details.

If you believe your device has been infected with spyware, it’s extremely important to quickly respond. For additional information, see our guide on how to remove spyware from iPhones.

Ransomware

In a ransomware attack, a hacker will lock your files and threaten to destroy or leak them if you don’t pay a fee. Unfortunately, you’ll likely only become aware of an attack once it’s already underway.

Security providers like TotalAV and Bitdefender offer anti-ransomware features, including secure storage, which can ensure your most important files are backed up and protected, and tools to prevent files from being encrypted.

This type of attack is particularly problematic for businesses and institutions with irreplaceable documents and data. See our guide to the best business antivirus software for business-specific tools.

Adware

Adware can be benign in cases in which it’s provided to promote a product or service. In other cases, though, it may allow malicious actors to access your system, track you, hijack your bandwidth and processing power, or steal your files and data.

Fileless Malware

Fileless malware attacks use macros and exploits to infect your system without you having to download an .exe file. Real-time threat protection tools may be able to detect and stop these types of infections. But you won’t be able to stop them by scanning an individual file, of course.

What to Check After Using a Virus File Scanner on a Downloaded File

After you scan a file for virus and malware indicators, you may wonder what to do next. If the scan came back clear, but you still have suspicions about a file, then there are a few things to look at that may confirm if the file is a virus or not.

  1. Check the Publisher

    If you’re concerned about a file, you can check to see if it has a listed publisher. Right-click on the file and check its properties.

    If the file is from a legitimate software company, such as Microsoft, its name should be listed as the publisher. If there’s no publisher shown or you don’t recognize it, it’s best not to use the file without further research.

    You can also check other details here, like the original file name, version numbers, modification dates, and security permissions. If any of these details seem odd, it may be an indication that the file isn’t legitimate. If you want to be completely certain that a file hasn’t been altered, you can also check the file hash, which can confirm the integrity of the file.

  2. Be Wary of .exe Files

    People often ask, “Are .exe files safe?” You should be particularly wary of them as they can be a fast track to installing malware on your device.

    They’re designed to install full computer programs and can be set to self-install, so malware can infiltrate your system without you even opening or running the .exe file. In fact, .exe files are the most common malicious file type today for files sent via the web and the second most common sent by email.

    <strong>Be Wary of .exe Files</strong>
  3. Run the File in a Sandbox

    False positive results are possible when using antivirus software file checkers. If you want to use a file and think it’s safe, you may want to test it in a sandbox.

    This is a virtual environment that’s kept separate from the rest of your computer system so files and software can be tested and run safely.

    Antivirus apps such as Avast offer sandbox environments so you can safely test files and run applications without putting your device at risk.

    <strong>Run the File in a Sandbox</strong>
  4. Continue to Monitor the File

    If you still have suspicions about a file – after having scanned it, confirmed that it looks legit, and potentially run it in a sandbox environment – then you can nevertheless continue to monitor its activity on your device.

    Using an antivirus app like TotalAV can help you monitor activity on your device in real time and detect potentially concerning behavior.

    Of course, it’s always sensible to be very wary of pirated software, to avoid opening suspicious emails, and to never download or open attachments from unknown individuals.

What Does a Virus Scan Do? How Can I Know If a File is Safe?

You may be wondering, what does a virus scan actually do? Antivirus software scans your computer’s memory for patterns suggesting the presence of malicious software and viruses – and it’s key to how to check if you have a virus.

Antivirus programs will generally let you select scan options, such as whether you perform a full scan, a scheduled scan, or a custom scan to check manually selected files. Antiviruses can also detect threats like fileless malware and malicious browser extensions, which may otherwise be hard to detect.

Some premium tools also run system optimization checks with their scans, searching for apps that require security patches or software updates.

When running a scan, scanning engines check files against databases of known security threats. Many modern security packages provide real-time protection and continuously monitor system activity to identify malicious behavior from previously unknown malware.

This allows them to find virus infections and novel, zero-day threats, and they can scan every downloaded file to ensure it’s safe.

When antivirus apps find a threat, they generally isolate the file by placing it in quarantine. This stops the file from interacting with anything else on your system and protects it from being compromised.

Once a file is in quarantine, your antivirus program will present scan results and give you options on what to do next. This may include removing the file or marking it as safe if it’s a file you trust.

If you find an infected file or folder on your device, it’s a good idea to run a full system antivirus scan with your antivirus app, as there may be other infected files on your system.

It’s also important to protect all your devices to ensure your whole digital ecosystem is secured and your desktop can’t be reinfected by your mobile device, for example. Check out our guide to the best Android antiviruses for securing mobile.

How to Know If an Image Has a Virus

Images can be used to spread viruses by hiding malicious code in their metadata – so it’s sensible to be wary of what you click on on Whatsapp and other online services. This includes JPEGs, PNGs, and GIFs. A common warning sign that a file may be infected is that it’s a much larger file than other similar images.

You can use an online file scan to check files before downloading them and detect viruses without exposing yourself. Most browsers allow you to right-click on images and copy the address or link where the image can be found. You can then enter this into an online file scanner to check if the file has a virus.

If you’ve already downloaded the file, you can scan it and quarantine it if needed using an antivirus like TotalAV. If you’re not sure if it’s a virus file, you can also check for additional red flags, such as whether its dimensions and the image property information, accessible by right-clicking, are what you would expect.

You should also watch out for spoofed file extensions. For example, a file might be called file.jpeg, but it’s actually a .exe file, which you shouldn’t open. In cases like this, your system won’t display the standard icon for a JPEG file, which may serve as a warning sign that something is amiss.

How to Check a Zip File for Viruses

Compressed files and archive files can contain folders and files and hence can be used to hide viruses and malware. There are even so-called zip bombs, which are intended to lock up your device as soon as they’re decompressed.

Fortunately, most modern antiviruses can scan the contents of a zip file, so you can check them like any other file. If you’re still suspicious, you can extract their contents and then re-scan them for additional confidence that the contents are safe.

Of course, as a rule, you should only download files from trusted sources, and if in doubt, you should always err on the side of caution.

Can a PDF File Have a Virus?

Yes, PDF documents can carry malware in the same way as .exe files. Hackers can inject malicious code into a PDF and infect your device with trojans, adware, or spyware. A compromised PDF can contain embedded scripts, JavaScript, or links to dangerous websites, which execute malicious processes when you open the file.

Your first line of defense against such attacks is checking the file for viruses via an online tool like VirusTotal or a free service like NordVPN File Checker.

Even if you’ve downloaded it, a malicious PDF usually can’t cause further damage to your system unless you open it, however. To stay safe, always scan downloaded PDFs with a reliable antivirus that can detect hidden threats before they have a chance to run.

How Can You Protect Yourself From Downloading Files Infected with Malware?

There are a number of steps you can take to ensure you’re safe from malware files. Here are a few to keep in mind:

  • Get an Antivirus – An important first step is to get a robust antivirus that can protect your devices and information. Here’s our guide on how to check for viruses with an antivirus.
  • Avoid Malicious Sites – It’s important to steer clear of untrustworthy URLs that may be hosting viruses and malware and will expose you to the “your file is ready to download” virus, among many others. In addition, try to make sure you only download software from official app stores and trusted sources.
  • Enable Phishing Protection – Make sure to use tools included with your antivirus to scan emails and websites for potentially malicious files and links.
  • Scan If In Doubt – If you’re ever worried, it’s best to manually scan the file for viruses immediately and, if you’re still uncertain, to quarantine or remove it, quickly gauging whether there’s a threat.
  • Secure Your Devices and Network – A single device can present a weak link in your defenses. So, it’s important to ensure you have robust protection for all your devices, across desktop and mobile, and for your router. Check out our guide to how to get rid of viruses on your phone for more details, and make sure you have a firewall in place to protect your network traffic.
  • Get a VPN and an Ad Blocker – Using a VPN will encrypt your internet connection, adding an extra layer of security. Providers like Surfshark also include an antivirus and ad and tracker blockers, which will stop you from being exposed to adware and pop-ups that can carry harmful code. See our guide to the best antiviruses with VPNs for more options and recommendations.

The Top Antivirus Software to Scan Files for Viruses

There are a number of excellent antivirus apps on the market. They offer far better defenses than built-in tools or free plans as well as incorporating key features like real-time protection and firewalls. The top solutions are generally very lightweight and have minimal performance impact.

Many of the best malware removal solutions also include additional tools such as password managers and data breach monitoring. These provide multi-layered security for your device and data and can secure multiple devices with a single subscription.

Based on my cybersecurity testing experience, here are my AV picks for scanning download files and links:

Antivirus Software Starting Price Antivirus Lab Testing Results Key Features Max Devices Free Version / Trial
TotalAV $19/year 17.5/18 (Protection: 6/6, Performance: 5.5/6, Usability: 6/6) Phishing Protection, Password Manager, System Optimization 8 Free Plan
Bitdefender $24.99/year 17.5/18 (Protection: 6/6, Performance: 5.5/6, Usability: 6/6) Ransomware and Spyware Protection, Password Manager, VPN 25 Free Plan, 30-day trial
Norton $29.99/year 17.5/18 (Protection: 6/6, Performance: 5.5/6, Usability: 6/6) Cloud Backups, Smart Firewall, Password Manager Unlimited 30-day trial
McAfee $39.99/year 17.5/18 (Protection: 6/6, Performance: 6/6, Usability: 5.5/6) Advanced Security Features, Protection Score, System Optimization Unlimited 30-day trial
Avast $35.88/year 18/18 (Protection: 6/6, Performance: 6/6, Usability: 6/6) Ransomware Shield, Automatic Driver Updates, VPN 30 Free plan, 30-day trial

Many people will be interested in downloading the best free antivirus solutions, but few of these include real-time protection and the ability to scan individual files with a virus file checker.

I recommend paid plans that offer more control over scans and a higher degree of overall security – and you can test them for free with a free trial. Having a good antivirus in place is key to how to search for viruses on PC.

For more information on how to check if there is a virus on your computer, read our guide on how to get rid of a virus on your computer.

How to Tell If a Download Has a Virus Using a File-Virus Scanner

How can I tell if I have a virus? If you’re concerned about the safety of an item you’ve downloaded, it’s a good idea to scan the file for viruses before you open it so you’ll know, “Is this file safe?”

On Windows computers, scanning a single file is simple. You can use a custom scan in TotalAV to scan the file for threats and have an answer in seconds. This is the best approach for how to know if a file is a virus. If you want to scan suspicious files for viruses online, VirusTotal is a good online file scanner. You can upload most types of files, and VirusTotal can check them.

If you find a threat, you need to take action quickly to protect your device. Antivirus software is key to how to check for viruses on Windows 11. It can help you quarantine files and test them so you can mark them as safe or remove them as quickly as possible.

Conclusion – How to Check Files for Viruses

If you find a suspicious file on your device or want to download a file from a potentially untrustworthy site, it’s a good idea to check whether the file is virus-free. If not handled carefully, a virus-infected file could cause serious damage to your device or even give cybercriminals access to your private information, including your passwords and bank account.

Because of this, I recommend using a reliable antivirus like TotalAV that will not only scan suspicious files and quarantine any threats but will also prevent you from downloading infected files in the future.

In this guide, I’ve covered how to tell if a file is a virus and how to check a download for viruses – but the key thing is to be cautious. Make sure that you’re on the lookout for signs of malware and suspicious behavior, as being mindful can save you a lot of time and trouble in the future.

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Tsvetomir Koychev
Editor

Tsvetomir is a tech-savvy Editor and Writer, focused on online privacy and security. With close to five years of experience in the field, he strives to simplify complex topics and fact-check every detail to ensure his readers always get the most accurate information.