How to Know If Your Computer Is Hacked FAST

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Is my computer hacked? We have all asked ourselves this question at some point. With cybercrime growing more common and disgruntled exes and co-workers finding new, digital ways to intrude upon our lives, it’s vital to learn how to tell if your computer is hacked.

Today, we’ll explain how computer hacking works and why it’s so dangerous. We’ll also share a detailed 15-point checklist to help you determine whether your computer is hacked. Keep this list handy while checking your desktop or laptop’s performance so you can stay a step ahead of hackers.

We’ll also tell you how to minimize the damage if you’re hacked and the necessary steps to take. Remember, with the right best practices, cybercrime can be prevented. Scroll down for guidance on how to tell if someone hacked your computer and measures to prevent it in the future.

What is Computer Hacking?

The term hacking essentially means hijacking a computer system. Interestingly, it doesn’t always occur with malicious intent. In 1969, MIT engineers became the world’s first hackers when they started breaking into and altering software and hardware to make it work better.

However, over the years, computer hacking has taken on new, scarier dimensions. While ethical and white hat hackers do exist, cybercriminals use hacking techniques to compromise user systems and find out secret information.

Modern hackers are often state-sponsored and aim for high-value targets. For example, in 2024, Microsoft identified a widespread attack on its systems from the Russian state-sponsored actor Midnight Blizzard. And who can forget 2017’s WannaCry attack that used malware to hack over 230,000 computers in a single day?

That’s why we need to ask ourselves that all too critical question, ‘How to know if your computer is hacked?’ Whether you’re a public sector employee, a software engineer, a student, or simply a professional in any industry relying on your computer for daily work, you could be the target of the next computer hack.

To always stay vigilant, you need to know the three types of computer hacking:

1. Black Hat Hacking

This is precisely why you need to know how to tell if a computer has been hacked. In black hat hacking, criminals target your computer, discover any vulnerabilities it may have, and exploit them. They could have a variety of motivations.

A black hat hacker could hold your data for ransom. They could be from a competing company looking to damage your reputation or sponsored by a nation-state. This type of hacking can inflict severe damage on your computer and others connected to it.

2. White Hat Hacking

White hat hacking doesn’t pose any danger to individuals. Instead, it is an activity commissioned by organizations and governments to test their computer systems from the perspective of hackers. It can be part of larger cybersecurity efforts like penetration testing and red teaming.

White hat hackers are hired to simulate cyberattacks and expose any vulnerabilities. Some companies even have bug bounty programs that reward white hat hackers for successfully discovering and reporting security flaws.

3. Gray Hat Hacking

This type of hacking occurs without the target’s permission but doesn’t have any malicious intent. Grey hat hackers aren’t looking to cause you harm or gain financially. Rather, they’re public activists working for the common good.

They might expose vulnerabilities in government systems or publicly reveal flaws that were covered up in the past. While gray hat hacking isn’t dangerous, it’s useful to know how to tell if a computer has been hacked. Knowing how to tell if a computer has been hacked can prevent reputational damage and help fix the issue faster.

What Are the Risks of Computer Hacking? 7 Key Dangers

So, how to know if your computer is hacked? Before we answer that question, we should first understand why we must identify hacking ASAP. Computer hackers can break into your system and wreak havoc in many ways, and these dangers also spill over into our offline lives.

1. Account Takeover

One of the biggest risks of computer hacking is account takeovers. The hacker gets hold of your usernames and passwords and logs into your online accounts. They could post on social media posing as you. Or, they might steal information stored in your business and personal accounts.

2. Financial Losses

A computer hacker could hijack your bank details and credit card information. They might make expensive purchases or request cash credit. Sometimes, hackers lock user data and hold it for ransom, providing the key only when you pay a hefty sum. All of this leads to financial losses.

3. Spying and Stalking

Someone might hack into your computer with the sole purpose of stalking or spying on you. It could be an unhappy ex or a disgruntled co-worker who develops an unhealthy obsession with what you’re doing online. If you feel your computer is hacked for this reason, spyware removal apps could offer a solution.

4. Botnet Infections

Botnets are large groups of computers on the same network that collectively cause cyber attacks. A criminal could hack into your computer, infect it with malware, and take control. Then, they mobilize all the infected computers to carry out attacks like DDOS.

5. Reputational Damage

Hackers who successfully access your social media accounts can cause a lot of reputational damage. For instance, in 2020, high-profile Twitter accounts, from Barack Obama to Elon Musk, were hacked to promote a Bitcoin scam. In today’s hyperconnected age, this risk makes it critical to learn how to know if your computer is hacked.

6. National Security Risks

Another risk you should be aware of is the growing danger to national security. State-sponsored actors often target computers owned by healthcare professionals, law enforcement, journalists, bureaucrats, and others who serve a country’s citizens. By compromising one system, these hackers might unlock a window into the larger network and cause severe damage.

7. Identity Theft

Hackers can commit identity theft by stealing your financial information, social security number, and other personally identifiable information (PII). They could use your identity to claim a tax refund or apply for a loan using your driver’s license.

How to Know If Your Computer Is Hacked? Common Warning Signs

The thing with computer hacking is that it isn’t always obvious. Cybercriminals work in the background, compromising your machine remotely without the user finding out before it’s too late. That’s why it’s so important to know how to tell if someone hacked your computer. Here are 15 tell-tale signs a computer is hacked:

1. Popup Ads and Messages

All modern computers ship with basic popups and ad blockers. These interrupting elements don’t appear as part of your usual browsing experience. So, if you suddenly receive pop-up ads, messages, and notifications when using your computer, it could be a warning sign.

Look out for pop-up messages that appear when you visit file download websites and peer-to-peer sites. Hackers might try to lure you with attractive ads (e.g., ‘80% off on Amazon’) or warnings (e.g., ‘your Windows subscription is expiring’).

Be even more careful about pop-ups that appear directly on your desktop, towards the bottom right, where your computer’s notification center is located. Fraudulent desktop popups are usually a sign that a computer is hacked.

2. Antivirus Warnings

If you have a good antivirus installed, it’ll probably tell you if your computer is hacked. However, hacking attempts are becoming increasingly sophisticated, and zero-day attacks are unknown to anyone.

Even then, antivirus software like Norton, Avast, SurfShark, and others will warn you when they encounter a suspicious file or spot unusual activity. Always heed these warnings. Quarantine the file immediately, avoid downloading the attachment, delete the file if possible, and disconnect your internet connection.

3. Suspicious Communications

Sometimes, our friends and family members may receive messages that don’t seem quite like us. They might seem out-of-sync with our personality or might make financial requests. These are signs that someone has hacked your account or set up a fake account using your data.

For instance, Facebook estimates that around 5% of its 3 billion+ users are fake. Fake accounts combined with personal data obtained from hacking can result in suspicious communication patterns. Look for promotional messages, crypto-transaction requests, and explicit images or texts sent on your behalf.

4. Unrecognized Programs

This is one of the oldest ways to know if your computer is hacked, and it still works in 2024. Note that these programs simply won’t just show up on your start menu. You’ll have to open your settings, go to ‘Add or Remove Programs,’ and view the full list of installed apps.

You’ll find a list of computer applications arranged alphabetically, complete with their publisher name, date of installation, and occupied space on the disk. Pay special attention to the publisher – if you find a Microsoft app published by someone other than Microsoft Corporation, it could mean you were hacked.

5. Password Reset Notifications

Another common sign a computer is hacked is when you receive frequent password reset notifications. It means that your account provider has recorded unusual access patterns. Perhaps the hacker attempted to break into your account at 1 AM, your local time.

In such scenarios, you’ll be prompted to change your password. The occasional password reset is absolutely fine and above board – even necessary for your security hygiene. However, if you receive these notifications several times in a month, it could mean you’re part of an ongoing hacking attempt.

6. Slow Performance

If your computer is working significantly slower than usual, it could be a sign of computer hacking. Do simple apps like Chrome take a long time to open? Do several black terminals open suddenly and then close when you boot up?

A good way to tell if your computer is running slowly is through the Task Manager. Right-click on the taskbar to open the Task Manager. Here, you’ll see how much computing resources (CPU, memory, disk, and network) are being consumed. If CPU usage is very high, it could mean your computer is hacked.

7. Laptop Overheating

For those who want to know if their laptop is hacked, overheating is one of the first signs to look for. Hackers consume a lot of resources to observe their behavior, collect data, and even install their own apps. Your laptop isn’t designed to accommodate this and ends up overheating.

If your laptop heats up even without heavy graphics activity like gaming or video editing, you should check for computer hacking and viruses. This is especially true for flagship laptops meant to run heavy loads or new devices whose CPUs are still very strong.

8. Drained Battery

Like overheating, a drained battery could also be a sign that your laptop is hacked. Users must be aware of the expected battery life of their device variants under real-world conditions – say, document editing, watching videos, internet browsing and a little bit of light gaming. If your laptop is performing substantially below the expected threshold, it could be a warning sign.

9. Strange Webcam Activity

A massive risk of being hacked is that the hacker might be able to control your webcam. This means that they can turn it on at any time and record your most private moments. This technique may also be used for corporate espionage.

Look out for any strange webcam activity, like the webcam indicator light being on even when you haven’t activated it, or the LED light flashing on and off. Double-check if any of your apps are using the webcam in the background. If not, it could be a sign that you were hacked.

10. Different Browser UX

The browser experience is one of the first things to be impacted when a computer is hacked. This is because the browser is a gateway to other computers on the network, allowing the hacker to spread the infection. As a result, you might notice a few unexpected changes in your browser’s UX.

It could be as innocuous as a sudden change to the dark theme. Your default search engine could be swapped from Google or Bing to something else. You might notice new extensions on the top right corner of your browser window, extensions that you haven’t installed.

11. Missing Files and Storage

When hackers take over a computer, they’ll typically infect system files or an entire disk. At first, they’ll be innocuous about it, making it hard for you to know if your computer is hacked. However, you can still keep an eye on it by checking your occupied storage space. Do you have a nearly empty drive that’s now suddenly full? Have you seen files and folders unexpectedly appear or disappear?

Let’s say you have a 16GB drive or external storage where you’ve kept 5GB worth of data. Yet, when you try to move new files into the storage space, your computer says that it’s full. This is usually a sign that there’s a virus in your system, and you need to take the correct steps.

12. Disabled Security Software

Most of us have security software or antivirus installed on our systems. This could be a free, built-in service, such as Windows Defender, which ships with modern PCs, or third-party software you have installed manually. Sometimes, the hacker will try to disable the software first before doing anything else to evade detection.

If you receive a notification that your security service is turned off but haven’t deactivated it yourself, it could be a sign that you were hacked. Check your notifications panel regularly to ensure this isn’t the case. You can also manually check that your defenses are activated by running a security scan every week.

13. Ransom Messages

If there’s a surefire sign that a computer is hacked, this is it. You might receive a ransom message that tells you your data is locked with a secret encryption key unless you decide to pay up. The hacker will typically include some sort of proof that the attack is real, such as some unique personal information or maybe the registration number of your hard disk.

Remember that hackers will disguise the message in a manner that doesn’t look like a direct attack or threat. If you’ve received such a message, it’s important to take immediate action, including, at times, informing law enforcement.

14. Multiple CAPTCHAs

While this isn’t always a sign that your computer was hacked, it’s one of the red flags that you should watch for. Let’s say you’re signing into a completely innocuous website like the Google search engine or your Outlook mail. But increasingly, you’re noticing that you have to complete a CAPTCHA challenge.

While CAPTCHAs are essential for security, seeing them multiple times a week is a warning sign. If your PC is experiencing this symptom combined with a few others on this list, you might run a virus scan.

15. Unusual Network Traffic

When computer hackers break into your system, they’ll typically want to connect to the Internet to run more large-scale attacks. They’ll likely do so at unusual times, logging into your account at odd hours of the day, or they might consume a disproportionately large volume of data. Look for patterns in internet consumption that deviate from your regular use.

What To Do if Your Computer Has Been Hacked?

Armed with the knowledge of how to know if your computer is hacked, you’re probably checking your PC right now for the warning signs.

If you notice two or more of these signs, it’s possible you were hacked. Don’t worry, all is not lost yet, and it’s possible to reclaim your digital presence even if you’ve been hacked. Here are some of the steps you can take:

1. Change Your Passwords

If you’ve been hacked, the first thing to do is change your passwords. This includes both software – your social media accounts, cloud storage, Google and Apple passwords, work apps, etc. – and hardware, including your router password. When you’re changing passwords, select the ‘log out of all devices’ option if available.

2. Disconnect from the Internet

You don’t want the hacker to infect others, so you need to turn off network access. Hackers can be extremely crafty and make it look like you aren’t online when you actually are. So, restart in Safe Mode without Networking to be absolutely safe. Turn off your WiFi router and unplug any Ethernet cables.

3. Remove all External Storage

If you suspect that your computer is hacked, you’ll want to salvage any storage or media you can. Go ahead and remove all your external storage appliances. Make sure not to plug them into a new system straight away. Instead, insert them into an old computer, if you have one, and view your files in Safe Mode.

4. Run an Antivirus Scan

You may have learned how to know if your computer is hacked, but you can’t pinpoint the cause or source of the attack. For that, you’ll need reliable antivirus software. These apps can run on-demand scans that detect suspicious files and folders on your computer. It’ll also assign a risk score and prompt you to delete or quarantine the file.

5. Block Your Credit Card

While it may seem like an extreme measure, blocking your card early on can save you a lot of trouble. Once the hacker has your data, one of the first things they’ll try is impersonate you for cash. So, block any lines of credit you may have to prevent financial damage.

6. Notify the Authorities

Depending on where you stay, you might want to inform the cyber cell of the local law enforcement department about the attack. It depends on the attack’s severity; if you’ve suffered a botnet hack, it may not warrant a formal communication. However, if someone is stalking you or impersonating you, immediately let the police and your banks know.

7. Switch to Safe Mode to Make Backups

Even if your computer is hacked, it doesn’t mean all hope – and data – is lost. You can still back up some of your information, although it’s best if you have done it beforehand. Restart your computer in Safe Mode and then plug in a new flash drive for backup. Individually copy the files you need; avoid copying folders or using Ctrl + A.

8. Format Your Hard Disk

The ultimate measure for hacked computers is formatting. This erases all your settings, files, data, and even the operating system, taking the virus along with it. Make sure to back up your essential files first and have an OS flash drive ready to reinstall and boot up your operating system.

How to Prevent Your Computer from Getting Hacked

Prevention, as they say, is better than cure. It’s much easier to follow a few best practices that can prevent hacking than it is to fix your accounts and get back your data after the fact. Luckily, there are several steps you can follow to prevent your computer from getting hacked:

1. Instal Antivirus Software

The best and most effective measure against hackers is antivirus. Software like TotalAV, Norton, and Avast can detect computer hacking attempts in real time.

If you’re wondering how to know if your computer is hacked, these apps will work silently in the background and monitor your computer for those warning signs we mentioned, automatically. What’s more, several of these options are available for free. They’ll also tell you if someone has hacked your accounts and exposed your private information on the dark web.

2. Update Your Apps and OS

Unfortunately, software developers don’t always get it right the first time, and the apps you use may have vulnerabilities. Also, new types of threats are always emerging, and developers are constantly rolling out new patches and updates to keep up.

To benefit from these, you need to install these updates on time. Too many of us avoid updating our computers until it’s enforced, which leaves us vulnerable to hacking. Turn on auto-update for all your PC apps and operating system.

3. Turn on Your Firewall

A firewall is a network security service that protects computers from dangerous connections. If a malicious app is trying to access the Internet from your PC, the firewall will stop it. Luckily, most modern computers come with built-in firewalls, so you don’t have to download or install anything.

Go to your start menu and open settings. From the security section, navigate to Windows Defender Firewall and make sure that the service is turned on.

4. Use a Password Manager

Hackers and cybercriminals often use a tool called keyloggers to get hold of our passwords. These dangerous apps monitor our every keystroke, relaying the data to someone sitting far away. As a result, they may find out the user ID and passwords to your online accounts.

You can prevent this by using a password manager. The best password managers autofill the password so that keyloggers can’t detect it. They’ll also store your passwords, user IDs, and other personal information in an encrypted vault. Powerful password management tools like NordPass can even tell you in real-time if your passwords or emails have been leaked.

5. Maintain Anonymity with a VPN

If hackers find out your internet protocol (IP) address, they can immediately locate and target you. To prevent this, use a virtual private network (VPN)—an app that sends your data through a secure tunnel so that your real location is hidden. For example, if you’re in Toronto, you could make it look like you’re in Paris.

VPNs are extremely useful for online security. Hackers can never find out your location, and some VPNs, like the excellent NordVPN, also stop you from clicking on malicious popups and ads.

6. Set up Multi-Factor Authentication

Another great way to beat hackers is through MFA, a process where you verify your identity more than once so that no one else can impersonate you. In MFA, you don’t just enter a static password – you also have to enter an OTP and may even have to complete biometric authentication.

To turn on MFA, open your app’s security settings and activate the 2FA or MFA option, whichever is available. You can also use a password manager like NordPass that comes with a built-in 2FA authenticator.

7. Avoid Using Public WiFi

Data passing through public WiFi networks is often unencrypted. This leaves you vulnerable to man-in-the-middle attacks, where a hacker intercepts your data before it reaches the router.

Computer hackers may also set up clone hotspots and WiFi networks. They lure you into connecting with an unsecured WiFi, which can then be used to inject malware. VPNs can protect you from some of the risks associated with using public WiFi, but it’s best to stick with trusted networks.

8. Regularly Backup Your Data

While backups can’t prevent hacking, they can lessen the impact, especially if you’re hit by ransomware. Instead of paying the ransom to unlock your data, you can simply resort to your backup. If your system is damaged due to a hack, backups also make it easier to recover.

Follow the 3-2-1 rule: three copies of data in at least two different formats and one copy off-site. This will protect you from hacking and other data loss scenarios.

9. Invest in an Email Attachment Filter

Hackers may use emails to carry out targeted phishing campaigns and inject malware into your system. Email clients come with a built-in spam filter, but it may not be enough. Choose an additional filter that can detect hacking attempts. You can also buy a good antivirus like TotalAV, which includes a powerful email attachment filter.

10. Learn About Phishing and Social Engineering

Computer hackers often rely on human psychology to bypass digital defenses. For example, looking up a person’s granddaughter’s name and birthday on Facebook might hold the key to their bank account password. That’s why it’s important to be vigilant and learn how to know if your computer is hacked.

During a social engineering attempt, hackers will rely on fear or greed to get you to part with information. They’ll try to scare you with an undesirable outcome—for example, ‘$200 has been deducted from your PayPal account. Click here to claim a refund.’

They could also offer you offers and promos that seem too good to be true. Be aware of these possibilities and use the Internet with a skeptical mindset.

11. Lock Your Laptop with Biometrics

This ties into what we were saying earlier about MFA. The physical security of your computer is just as important as your online accounts, so protect it using biometrics. Most Windows PCs today come with the facial recognition service Hello. You can also lock your MacBook using Touch ID, Apple’s fingerprint scanner for PCs.

12. Download With Caution

File downloads and peer-to-peer sites like BitTorrent are common causes of viruses getting into our computers. Since these websites don’t always get legit ads, they may show you ads and pop-ups from hackers. Once you download them, they might also contain corrupt files that allow hackers to break in.

While it may not be possible to avoid these websites entirely, it’s vital that you proceed with caution. Avoid signing up for services, which could expose your email. Scan all your downloads using an antivirus like TotalAV.

13. Pay Attention to Privacy Notices

Modern websites collect a ton of data on user behavior to personalize your experience. However, they might also sell this data to untrusted third parties, including hackers. When a website tells you to enable cookies, they’re essentially asking for your permission to collect data.

When you visit different websites, pay attention to these requests and notices. Check out what exactly you are agreeing to—will the cookies help improve website performance, or will they collect data for vague marketing reasons? Avoid activating anything but the necessary cookies.

14. Adopt the Principle of Least Privilege (PoLP)

According to the Principle of Least Privilege, or PoLP, you should not grant access rights unless absolutely necessary. A great way to enforce this is by creating two separate accounts on your computer, admin and regular. Use the former only when you need to create backups or make system changes.

Otherwise, use the latter for your daily work. That way, even if a hacker manages to break in, your Windows account won’t give them the right to modify the system.

Is My Computer Hacked? Here’s The Bottomline

While some signs of hacking may be obvious, it isn’t always easy to know if a computer is hacked or what is the extent of the damage. That’s why we have provided you with a simple, 15-item checklist. If your computer has experienced two or more of these symptoms within a short period, it could mean you’re hacked.

Even as cybercriminals become more sophisticated (some even sell their services to regular users on the dark web), there are steps you can take to beat them. Follow proper password hygiene, invest in a good security toolkit – antivirus, VPN, and a password manager – and beware of psychologically driven social engineering attacks.

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