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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 total 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.
Best Antivirus Software to Scan Files for Viruses
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How to Scan a File for Viruses
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, perhaps you want to scan a file from an unfamiliar website before downloading it to your device.
You should be particularly wary of .exe files, which can install programs on your device. Nevertheless, the number of infected Microsoft Office files has dramatically increased in recent years, and PDF and .docx files are by no means guaranteed to be safe. At the same time, the number of never-previously-seen malware variants is increasing every year.
But worry not – here’s a detailed step-by-step guide on how to scan a file for viruses before downloading it, either on your computer or online:
How to Scan Files for Viruses on Windows with Antivirus Software
Norton is one of the best antivirus programs around. It makes file scanning very easy, as it offers real-time protection and can scan files for viruses before downloading completes to stop infected files from reaching your system.
Here are step-by-step instructions on how to scan downloads for viruses:
Open Norton
If you don’t have an account, go to Norton, sign up for a subscription, and download the software. When that’s complete, launch the Norton app on your device.
Go to Custom Scans
In the main window, go to the Security tab and then Scans. Next, go to Scans and Tasks and select the Custom scan type.
Choose the Files or Folders to Scan
From the Custom scan page, you can pick to scan a specific drive, folder, or file. By pressing control, you can also select multiple files to be scanned.
Results Summary
Once the scan has finished, you’ll get a Results Summary page with detailed information on the scan results. To leave this, click Finish.
If the scan has detected issues, these will be flagged in the Threats Detected pane. You can check these and then confirm whether you want to take Norton’s recommended action or actions. The file virus scan is now complete.
You can also run a virus check on a folder with Norton, and the process of how to check a file for viruses with McAfee is very similar.
How to Check a File for Viruses with Microsoft Defender
If you’re using a Windows PC, you’ll have access to a built-in antivirus tool called Microsoft Defender Antivirus, also known as Windows Defender, that enables you to scan a file for viruses on Windows 11. Here’s how to check if a file has a virus with Defender:
Windows Security
Open Windows Security on your PC and select the Microsoft Defender Virus & Threat Protection tool.
Pick a Scan
Select Scan options, then Custom scan. Windows Security will ask you what file or folder you want to scan. Click Select file where relevant, and Windows Security will scan it.
Results
If Windows Security finds a threat, it will present you with options on what to do next. If no threat is found, Windows Security will show No current threats – it’s determined that the file is safe, and you don’t need to take any further action, so you’re all set.
While a Windows-native Microsoft Defender is very functional, Norton and TotalAV can run much more comprehensive system scans and quick scans, compared to the former. And, unlike Microsoft Defender, they come with additional features to provide multi-layered security and protect against ransomware and phishing attacks.
How to Scan a File for Viruses Online
VirusTotal is a good option if you want a free service to scan a file for viruses online. The service uses multiple antivirus databases that come from different security vendors.
It’s a good file checker for virus scans, but keep in mind that you shouldn’t upload files containing personal or sensitive information. Here are the steps to take to upload and scan a file:
Go to VirusTotal and Pick a File
Go to the VirusTotal website, VirusTotal.com, and upload your file. Click Choose file and select the relevant file on your computer, or drag and drop it into your browser window.
Scan
VirusTotal will then scan the file using the latest virus data from multiple antivirus providers.
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.
You should then use antivirus software on your computer to quarantine or remove the original file – TotalAV and Norton are both robust solutions, and additional recommendations are listed further down the page.
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.
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 the file, then there are a few things to look at that may confirm if the file is a virus.
Check the Publisher
Firstly, if you’re concerned about a file, you can check to see if the file 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, then this should be listed as the publisher. If there’s no publisher shown or you don’t recognize the company, it’s best not to use the file without further research and checking additional details.
Be Wary of .exe Files
“Are .exe files safe?” is a common question. You should be particularly wary of them as they can be a fast track to installing malware on your device. In fact, .exe files are the most common malicious file type for files sent via the web and the second most common sent by email.
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.
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 might consider testing 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.
Continue to Monitor the File
If you still have suspicions about a file – having scanned it, confirmed that it looks legit, and potentially run it in a sandbox environment then you can still continue to monitor its activity on your device.
Using an antivirus app 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 access attachments from unknown individuals.
What Does a Virus Scan Do? How Can I Know If a File is Safe?
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.
Some premium tools will also incorporate system optimization checks into 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, monitoring system activity to identify malicious behavior from previously unknown malware.
This allows them to identify novel viruses and zero-day threats. They will often also scan each 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 your other files and data from being compromised.
Once a file is in quarantine, your antivirus app will present scan results and give you options on what to do next, such as 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 make sure your whole digital ecosystem is secured – check out our guide to the best Android antiviruses for securing mobile.
What Can Virus Scans Find?
Having covered how to check if a file has a virus, I’ll now explore just what a file virus checker can find. In short, virus scans primarily aim to identify malware and infected files on your system. 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.
Trojans
Trojans are a type of disguised malware program that appears to be safe to use but gives hackers access to your system and files. In some cases they may hide or alter their original file name to escape detection.
Spyware
Spyware tools allow third parties to track activity on your device or to control the device itself – potentially putting you at great risk and exposing you to identity theft and fraud.
Ransomware
In a ransomware attack, a hacker will lock your files and threaten to destroy them or release them if you don’t pay a fee.
This 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 is provided to promote a product or service. In other cases, though, it may allow malicious actors to access your system, track you, or steal your files and data.
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 product that can protect your digital devices and your information. Here’s our guide on how to check for viruses with an antivirus.
- Avoid malicious sites – It makes a big difference to steer clear of untrustworthy URLs that may be hosting viruses and malware. 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 about a file, it’s best to scan it immediately and, if you’re still uncertain, to quarantine or remove it.
- Secure your devices and network – A single device can present a weak link in your defenses, so it’s important to make sure you have robust security in place 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 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 generally offer far better defenses than built-in tools or free plans as well as incorporating key features like real-time protection. The top solutions are generally very lightweight and have a minimal performance hit.
Many of the best malware removal solutions also include additional tools such as password managers and data breach monitoring to 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 | Test Results | Top Features | Max Devices | Free Version / Trial |
|---|---|---|---|---|---|
| TotalAV | $19/year | Protection: 5.5/6, Performance: 5.5/6, Usability: 6/6 | Phishing Protection, Password Manager, System Optimization | 8 | Free scans |
| Norton | $29.99/year | Protection: 6/6, Performance: 6/6, Usability: 6/6 | Cloud Backups, Smart Firewall, Password Manager | Unlimited | 30-day trial |
| McAfee | $39.99/year | Protection: 6/6, Performance: 6/6, Usability: 6/6 | Advanced Security Features, Protection Score, System Optimization | Unlimited | 30-day trial |
| Trend Micro | $19.95/year | Protection: 6/6, Performance: 6/6, Usability: 6/6 | Ransomware and Phishing Protection, Secure Browser, Folder Shield | 10 | Free tools, 30-day trial |
| Avast | Free / $35.88/year | Protection: 6/6, Performance: 6/6, Usability: 6/6 | Ransomware Shield, Automatic Driver Updates, VPN | 30 | Free plan, 30-day trial |
Check out our guide to the best antivirus software for more details on these options and other file scanners.
Many people will be interested in downloading the best free antivirus solutions, including picks like AVG Antivirus, but few of these include real-time protection and the ability to scan individual files. I recommend paid plans that offer more control over scans and a higher degree of overall security.
How To Tell If a Download Has a Virus Using a File-Virus Scanner
With the growing number of threats online, it’s important to be vigilant. 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 can answer the question, “Is this file safe?”
On Windows computers, scanning a single file is simple – you can use a custom scan in Norton to scan the file for threats and have an answer in seconds. It also has real-time protection and web protection features and will stop your system from downloading malware-infected files.
If you want to scan suspicious files for viruses online, VirusTotal is a good online file scanner. You can upload almost any kind of file, and VirusTotal can check it.
If you find a threat, you need to take action quickly to protect your device. Antivirus software can help you quarantine files and test them in a safe sandbox environment so you can mark them as safe or remove them as quickly as possible.
Conclusion – How to Check Files for Viruses
If you stumble across a suspicious file on your device or want to download a file from a sketchy 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.
Because of this, I recommend using a reliable antivirus like Norton that will not only scan the suspicious file and quarantine any threats but will also prevent you from downloading infected files in the future.
FAQs
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References
- Understanding Anti-Virus Software (CISA)
- Most common malicious file types received globally via web and e-mail in 2022 (Statista)
- TotalAV test results (AV-Test)
- McAfee test results (AV-Test)
- Norton Internet Security test results (AV-Test)
- Avast Free Antivirus test results (AV-Test)
- SonicWall’s Mid-Year Cyber Threat Report Finds Malicious Microsoft Office Files On Rise, Ransomware Up in US, Globally (SonicWall)
- SonicWall Threat Data Exposes Depths of Cyberattacks; Propels the Need for Managed Service Providers (MSPs) (SonicWall)
