How to tell if you have malware
Don’t panic. Just because your computer started doing something strange doesn’t mean you’ve been hacked. We’ll teach you how to tell if you have malware and what to do if you think you’ve been affected.

Signs of malware
The symptoms of a malware infection can also be signs of other problems – not necessarily of a nefarious nature. This guide will help you identify the issue before you go full-steam ahead with scrubbing your machine head-to-toe with anti-virus software.
1. Your device is slower than usual
This is one of the most common signs of malware. The program will consume your system resources and prevent the device from running at peak efficiency. Before you get trigger-happy with your antivirus suite, know that there are countless other issues that can cause a loss in performance.
You might have left a performance-draining program running in the background and forgot to end it. If this issue persists, then continue reading to identify if any other symptoms are showing.
2. Slow internet connection
One of the signs of potential malware, is your devices process’ slowing down to a snail’s pace. Remember to assess everything else before assuming it’s an infection. If other people are on the Wi-Fi network, check with them to see if they’ve been hogging the bandwidth. In the case of malware, it could be using the Wi-Fi connection to send your data on to hackers.
3. Suspicious data consumption
Your service provider will typically keep logs and inform you of what your average monthly data usage is. If not, you’ll have a rough idea if you’re regularly getting messages warning that you’re approaching your data cap.
If you’re getting those messages sooner than usual, it’s time to review your latest app additions. Some background apps will be using data you’re not aware of. Malware works similarly, siphoning off your data for its own purposes. If your online habits haven’t suffered any upheaval recently and you’re bleeding data quicker than usual, this could be a sign of malware.
4. Suspicious pop-ups/notifications
If your device is starting to get pop-ups when you’re working offline, it’s a clear indication that malware is currently present. Usually, it will just be a piece of software that uses aggressive, invasive tactics to get you to pay up and remove it. The pop-ups may be annoying, but do not, under any circumstances, provide them with your payment information.
5. Device crashes
Your device frequently crashing could be the sign of an overworked and faulty setup – or it’s a symptom of a freshly installed virus. How long has your computer or device been crashing for? Look at your most recent downloads – there’s a chance you could have unknowingly downloaded a file or app that harbors malware.
6. Messages you didn’t send
Have your friends been asking you to stop sending spam emails? You’ve got malware. Some malware will crawl into your email account and use it as a springboard for a phishing scam. These emails could contain malicious links or infected files. Other scam emails will ask everyone on your contact list to transfer money to a bank account owned by the hacker.
7. Apps or programs you didn’t download
Downloading what may seem like a legitimate app could potentially come bundled with a sneaky malware injection alongside it. Pay close attention to your desktop – are there any new icons that you don’t recognize or personally install?
The toolbar on your browser is also a common hiding place for any unwarranted infections. For those who know their devices like the back of their hands, noticing any unexpected changes will be the first sign that something could be wrong.
8. Unresponsive system
Some malware can be purged using certain system tools. Unfortunately, more sophisticated malware can deny access to those tools. If your device is restricting you from accessing system admin tools, then it’s a clear sign that your computer is ridden with malware.
9. Disabled security programs
Enabling your security programs should be the first thing you do when you boot up your computer or turn on your device. Most firewalls, malware detectors and other such software can be set to turn on when you log in.
However, if you’ve found that your security measures have been disabled or even deleted, malware may have wormed its way into your device and greenlit the path for more infections to take root.
10. Locked files/folders
Take into account that most malware is designed to be insidious – it sneaks in and lays low. Others kick the doors down and announce their presence by immediately locking down access to your device.
This kind of malware will keep your files encrypted and leave you unable to access them. Whoever sent the virus in the first place will send a message and demand payment. Hence the name – ransomware.
11. Redirects while browsing
Keep an eye on your URL, especially when the page you’re looking to browse is loading. Some malware can mimic your homepage or a favorite website you regularly use. It does this to collect your account details once you’ve entered them into the bogus site.
The next time you’re loading up your banking app or any other website that needs your sensitive information, pay attention to the URL. Make sure it corresponds with the official address used by the original website.
How to protect yourself if you already have malware
Your first concerns once you’ve determined that you have malware is to isolate it or remove it from your device. Anything you do on your device may feed your attacker more information, and some more sophisticated attacks are capable of preventing you from stopping them. The specific course of action may depend on your device and the malware, but here’s a general guide:
1. Re-secure your device
The tools at your disposal will depend on your device, but you want to flush the malware out as soon as possible. One or more of these should work for you:
- Delete the app: If the malware was delivered by or consists of a suspicious app you just installed, remove it as soon as possible.
- Disconnect: Many types of malware will need a connection to the internet to complete their attack. You can cut off these connections to buy yourself some time. Data, bluetooth, Wi-Fi – all of it can be disabled.
- Antivirus scan: If you have an antivirus suite, use it to perform a full scan of your system. It should be able to detect and quarantine the malicious code on your device.
- Turn on safety mode: Many devices can boot in a safety mode which limits functionality to just the essentials of your system. This is especially useful if the malware is making it difficult to use your device. After booting in this way, you can take steps to remove the malware and secure your credentials.
- Factory reset: This is often called the “nuclear option”, but it will be effective for nearly all types of malware. Resetting your device to the condition it came in out of the box will wipe everything from it, including the malware. You will have to reinstall your apps and adjust your settings from scratch.
2. Mitigate the damage
Your next step is to prevent any damage that might be caused by data that the malware might have stolen. This step will also be determined by the type of malware you got and how you became aware of it. Depending on the situation, you may want to consider one or more of the following:
- Contact your bank: If you think the attacker may have the credentials needed to perform transactions with your money, notify your bank. Some banks have systems allowing them to place potentially compromised accounts under greater scrutiny.
- Change your passwords: If you think the attacker may have gotten a password to one or more of your accounts, change those passwords as soon as possible. This, by the way, is the reason why using a different password for each account is so important. If you recycle passwords, then a breach will allow the attacker to gain access to all of your accounts.
- Warn your friends and loved ones: Some malware lets attackers pretend they’re you, using your identity to steal money from friends and loved ones. If you think this might be the case, be proactive – notify friends and family that your account may have been compromised. It may be a bit embarrassing, but dealing with the breach of trust after a scammer used your name to steal money from people you know can be worse.
3. Re-secure yourself
Now that you’ve eliminated the threat and prevented it from causing further harm, it’s time to make sure it doesn’t happen again!
- Use a VPN: A VPN will encrypt your traffic, making it far harder for certain types of malware to infect you.
- Use Threat Protection: In addition to secure VPN service, NordVPN also provides a tool called Threat Protection. This scans the files you are downloading for known malware, making you much more secure.
- Learn to avoid malware: Read about the most common types of malware so you can learn about how to avoid them.
- Strengthen your passwords: Use a different password for every account, and use strong passwords that are hard to guess. If remembering all those passwords sounds daunting, check out NordPass – our comprehensive password manager.
- Always install updates: Some types of malware will rely on vulnerabilities that developers try to fix as soon as they’re discovered. They fix them by sending updates to users. Always download and install updates, because they may contain critical security fixes.
Want to read more like this?
Get the latest news and tips from NordVPN