Updated on: April 26, 2024
Short on time? Here’s how to quickly check if a file is safe to download:
- Install reliable antivirus software. Choose a top antivirus like Norton, so you get every feature you need to stay safe, plus a flawless malware scanner.
- Run an antivirus scan. Run a custom scan on the file you want examined, or a full scan if you think the infection has spread. This will tell you if the file contains malware and help you remove it.
- Turn on real-time protection. Real-time protection blocks threats before they’re executed, so they can’t infect the rest of your device. Having real-time protection is vital to avoid malware taking root in your files.
- Turn on web protection. Most unsafe files come from shady websites, phishing scams, and suspicious links. Web protection prevents you from going into these fraudulent websites and filters phishing scams automatically — so you never accidentally click one.
- Follow tips and tricks for online safety. These are basic but important. Check the website’s domain to make sure it’s official, don’t click on links unless you’re completely sure the link is safe, and don’t open files from an email sender that you don’t recognize.
Before you download a file, ask yourself if you’ve checked whether it’s infected with malware. Downloading a file that you haven’t checked can easily wind up with you accidentally downloading malware onto your device, resulting in it draining your resources, spying on you, or helping hackers take full control of your network.
Fortunately, there are a lot of tell-tale signs that a file has an infection, as well as tools you can use to check a file and stay safe in the future. On top of basic tips, like never downloading a file from a suspicious website, a good antivirus will also keep you safe.
Norton is my top antivirus for checking if a file is infected in 2024. In addition to a flawless malware scanner, its real-time protection works great alongside its web protection to prevent you from downloading infected files in the first place.
How to Check if a File Has a Virus Before Downloading It (Step-by-Step Guide)
It’s actually pretty easy to check if a file is malicious. On top of some common safety practices that you should always follow, installing a good antivirus is important. I’ll be using Norton as my example — but the same steps and rules apply regardless of antivirus. That said, the specifics on how to run a scan or turn on features will vary.
Step 1. Install Reliable Antivirus Software
The first line of defense against cyber threats is having a reputable antivirus. Norton’s diverse range of protection tools and its robust threat-detection capabilities have earned its spot as my favorite antivirus in 2024. I’ll mostly be giving instructions on using Norton in this guide.
To install Norton, head to the website, choose your preferred plan, and purchase it. Click the link to download, and when the download is complete, open it from your file manager. The installation wizard will then walk you through the process of setting Norton up, though you’ll have to accept a few prompts and customize your settings.
Make sure Norton’s updated to the newest security patch, so you’re not vulnerable. It should do this automatically, but you can also go to the Device Security tab, use the dropdown menu, and click on the Live Update button. Norton will update itself if there are any pending updates.
Step 2. Run an Antivirus Scan
Once you’ve set up your antivirus software, it’s time to scan the suspicious file. Each premium antivirus software on my list allows you to run a quick scan, a full scan, or a custom scan of individual files. Opt for the third option. Click File Scan (or a similar alternative) and navigate to the file you’re concerned about. Finally, hit the Scan button. (Note: You can also right-click on the file and scan it using your antivirus software that way).
If you’ve already opened the file outside of your antivirus, you may have a bigger malware infection. In these cases, you need to execute a full scan by selecting the Full Scan option. It might take over an hour, as every single file on your device will undergo a thorough malware check, but it’s important you run the scan until the very end.
Whichever antivirus you choose will quarantine damaged files and let you remove them (or whitelist them in the rare situations where it flags a file you want to keep).
Step 3. Turn on Real-Time Protection
Real-time protection will defend you against malware before it can activate. While it’s on by default in most antiviruses, it’s always worth checking. Open up Device Security (or a similar alternative in your chosen antivirus), then click on the drop-down menu for Security. Afterward, just click the Advanced tab, and you’ll see whether Auto-Protect is turned on or off. If it’s off, just toggle it back to “On” to ensure you’re getting the real-time protection you paid for.
Step 4. Turn on Web Protection
Web protection allows you to avoid phishing scams and stops you from visiting unsafe websites — so it’s important to ensure you’re using it while online. A lot of threats mask themselves as legitimate companies or offers, so without good web protection, you’re at the mercy of the website you’re visiting.
To turn on web protection, go to Device Security (or a similar alternative in your chosen antivirus) and then click on the Internet Security tab. If web protection isn’t turned on already, click on Set Up Now if you’re using Norton and install the Norton Safe Web extension. You’ll have to follow a few prompts, but afterward, your browsers will be using Norton’s advanced security features to protect you while you browse the web.
Step 5. Follow Tips and Tricks for Online Safety
You can filter through most online dangers by following practical safety advice. For starters, it’s wise to refrain from opening suspicious files. If you can’t identify the source of a file or something about it just doesn’t feel right, it’s better to steer clear to avoid accidentally downloading malware.
Infrequently downloaded files are considered very risky — if you can, check for how many other users have downloaded a file, its upload date, and any reviews it has, so you can get an idea of whether it’s a popular file or not. Look to see if the file size matches up with what you’d expect from a similar download, too — a bulky PDF file or particularly small video file may be malware in disguise.
The same rule applies to links, especially those embedded in emails, instant messages, or social media posts from people you don’t know. Clicking on them could lead you straight to a malicious site or cause an immediate malware download. Always verify the source of any emails you receive and don’t trust spam messages with links from people you don’t know.
Norton offers an email screening service that takes some of the guesswork out of avoiding online threats. You can connect Safe Email to up to 5 addresses. Once you do so, all incoming messages will be screened for dangerous files and other threats. Safe emails will be marked in green while suspicious ones are given a red tag. It wasn’t perfect in my tests, so you should still use caution, but it’s better than nothing. The service is available as an add-on for any Norton bundle.
Criminals often use social engineering tactics like masquerading as a legitimate website or vendor — that’s why it’s important to always check a company’s domain (even a real-looking one) to make sure the URL matches up with the official website’s URL. You should also ensure the URL is verified with SSL (meaning it says HTTPS, not HTTP).
Remember the timeless advice: if it’s too good to be true, it probably is. A prime example is the common “job scam,” where bad actors will use a high-paying position to trick people into downloading a file containing malware or giving the hackers personal information.
3 Best Antiviruses for Protecting Against Unsafe Downloads in 2024
Quick summary of the best antiviruses for protecting against unsafe downloads:
- 🥇 1. Norton — Best overall antivirus for checking infected files in 2024 (100% malware detection rate).
- 🥈 2. Bitdefender — Feature-rich antivirus with a lightweight scanner that doesn’t slow down your system.
- 🥉 3. TotalAV — Beginner-friendly antivirus with an excellent malware scanner and web protection.
What To Do If You’ve Downloaded a Malicious File
If you suspect you’ve downloaded a malicious file, don’t panic. Start by disconnecting your device from the internet to prevent the malware from spreading or communicating with its controller.
Next, you’ll want to run an antivirus program. While I’m using Norton as an example (because it’s my favorite antivirus in 2024), any of my favorites will work.
To start, launch the antivirus and run a thorough system scan. This allows it to assess every file in your system and compare them to its expansive database of known threats. If the antivirus detects any signs of malware (like irregularities), it will promptly alert you and quarantine the suspicious file, letting you choose whether you want to completely remove it from your device.
How Do Infected Files Get Onto Your Device?
Malicious files infiltrate your device through various techniques used by cybercriminals:
- Phishing scams. Emails disguised as coming from legitimate sources may contain malicious attachments. Scammers also often use social engineering tactics (like a free prize or lottery win) to incentivize you to download their files.
- Torrenting. Free or discounted content such as movies or games might contain hidden malware. Remember that even popular torrenting sites may contain malicious downloads. Here’s a list of our best VPNs for torrenting, just so you can stay safe if you are planning on torrenting.
- Third-party app stores. These platforms lack rigorous security checks, leading to the circulation of apps with embedded malware. Sometimes, the whole app store could be a sham. Make sure you only download apps from reliable sources like the Apple App Store or the Google Play Store.
- Drive-by downloads: Visiting infected websites can automatically trigger malware downloads. This is why good web protection like that offered by Norton and Bitdefender is so important while browsing.
- Exploitation of vulnerabilities. Outdated software can be manipulated to introduce malware, so it’s always a good idea to keep everything on your computer up-to-date. Many antivirus programs (including Bitdefender) have vulnerability scanners that can do this for you.
It’s important that you always double-check email attachments, update software regularly, and only download from trusted sources. Even with the best antiviruses, like Norton or Bitdefender, you still have to remain vigilant online (though they certainly help!).
What Can Happen if You Download an Infected File?
When you download an infected file, you unknowingly invite many threats onto your computer. For example, you might download a .exe file masked as harmless software, only to find it’s actually a virus wreaking havoc on your system. Be careful of PDFs, Word documents, spreadsheets, image files, movies, games and mods, and more (between you and me, just be careful of every file).
Malicious files could be ransomware, locking up your data and demanding payment for its release. Office documents can carry macro viruses, resulting in data corruption or even covert surveillance of the whole organization!
Some files host trojans, opening backdoors for hackers to take control of your system. You might even become an unknowing participant in a botnet, with your device being used to launch attacks on other systems. Additionally, keyloggers could record your keystrokes, stealing sensitive information like passwords and credit card numbers.
Best Ways to Avoid Virus-Infected Downloads
There are a lot of ways to fall victim to online hackers, so staying safe online requires vigilance and a few key practices you have to remember:
- Use a reliable antivirus. Always keep a reliable antivirus like Norton installed and updated. It will actively scan and protect against dangerous downloads.
- Use a VPN: Use a VPN to encrypt your online activity and keep your privacy protected. While Norton and Bitdefender both come with good VPNs, there are quite a few great standalone ones.
- Verify a website’s domain before downloading. Download files only from trusted and verified sources. If unsure, do a quick bit of research about the website’s reputation and check its domain to make sure it’s the official version of the website. Remember that some deals are too good to be true and that a 90% sale on a misspelled Amazon domain probably isn’t real.
- Avoid unsolicited downloads. Do not download files from unsolicited emails or messages. Emails can be home to incredibly nasty threats.
- Remember updates and patches. Keep your OS and software updated. Regular patches often fix security vulnerabilities.
- Use a firewall. A good firewall can block malicious inbound and outbound traffic.
Frequently Asked Questions
What types of files can be infected?
Any type of file can be infected with malware, though some are more commonly targeted than others due to their ubiquitous nature and the fact they are often used to share information. These include PDFs, Word documents, Excel spreadsheets, and other data files. Unfortunately, even seemingly harmless image files or MP3s can harbor malware.
It’s crucial to consider the source of the file. Trusted sources are generally safe, but files from unknown or suspicious sources can pose a risk. Antivirus software scans all types of files, ensuring a thorough check irrespective of the file type.
What kinds of viruses are usually in infected files?
Infected files can contain a wide range of viruses, all beaten by a good antivirus like Norton. Common types of malware you’ll find in a bad file include:
- Trojans. They disguise themselves as legitimate software to trick you into downloading them.
- Worms. Replicate themselves so that they can take over your entire device or even network.
- Ransomware. Encrypts your data before hackers attempt to ransom it back to you.
- Spyware. Collects information about your activity, which is usually sold online or used for further malicious assaults.
- Adware. Displays unwanted ads against your consent, usually constantly popping up, slowing down your device, and acting as a gateway to further malware.
Can I download infected files on my phone?
Yes, unfortunately, mobile devices are not immune to malware. You can unwittingly download an infected file onto your phone, just like on a PC. This can occur when downloading attachments, apps from unofficial sources, or even through compromised Wi-Fi networks.
Both Android and iOS devices can fall victim to malware, which is why it’s important to have a reliable antivirus app on your phone too.
How do antiviruses get rid of malware?
Antivirus software employs several strategies to identify and eliminate malware. It relies on malware databases to recognize known threats but also uses heuristic analysis to detect new or modified malware strains. Once the antivirus detects a malicious file, it places the file in quarantine to prevent the spread of the malware.
The antivirus then attempts to clean the file by removing the malicious code. If this isn’t possible, the file may be deleted entirely to ensure the safety of the system. It’s also worth mentioning that you need real-time protection to stop the infected file from getting downloaded in the first place and web protection to block online phishing scams.
