How to Tell If Your Computer Has Been Hacked

Hacking, most of the times, isn’t personal. Hackers carry out massive campaigns and you might just be unlucky! Learn how to detect it, and how to react.

Hackers are after you. They want your personal information. They want control of your devices. They want your money. They want… just about anything they can get their hands on. Scared? Hacking of personal digital devices is a serious issue in cybersecurity, though it’s not always as threatening as you might imagine. In some cases, legitimate concern is warranted. Other times, you’re dealing with a nuisance (but who wants that?).

This article focuses on how to tell if your computer has been hacked. Hacking can affect Macs, Windows 7 PCs and Windows 10 machines as well as iOS and Android devices. We discuss how to prevent hacking and stop hackers once they’ve invaded your life.

Is It Likely That My Computer Has Been Hacked?

Are you likely to suffer from a hack? Research suggests that it’s a definite possibility. According to Krebs on Security, consumers should contemplate two realities in effect today:

  • Reality #1: Hackers already have access to aspects of your personal that you may believe should be secret, but which are not. These include your credit card info, social security, mother’s maiden name, date of birth and so forth.
  • Reality #2: Any data point you share with a business will almost certainly be hacked, lost, leaked, stolen or sold at some point in the future. When this happens, if you’re an American, your recourse is quite limited.

Why Do Computers Get Hacked?

Hackers want access to your data. Don't let them get it!

Hacking is usually a crime. Although it involves electrons, bits, and bytes, the hacker is breaking into your property. His or her goal may be simple malfeasance, as you might see with malware that slows your system for no discernable reason. While in other cases, hacking is the result of intelligence activity, with foreign governments trying to steal data about Americans and corporations. Mostly, though, hacking is a financially-motivated crime.

Hacking can take several forms:

  • Identity theft – if a hacker can steal certain pieces of information about you, like your name, address, birth date and social security, he or she can impersonate you and take money out of your bank account or borrow money in your name (and not pay it back).

    This is known as identity theft or identity fraud. It affects millions of Americans every year  . Hackers steal identities by penetrating your digital devices and looking for your personally identifiable information (PII). They can accomplish their goal through malware that searches and exfiltrates your PII or through eavesdropping on messages you send. Typically, the hacker sells your PII to someone else, who then engages in identity fraud against you.
  • Phishing – in a phishing attack, the hacker tries to trick you into clicking onto a link in an email or text message that sends you to a website that either downloads malware onto your device or fools you into divulging personal information through a bogus web form.

    Phishing attacks have grown highly sophisticated, with the attackers creating perfect copies of websites for banks, airlines and so forth.
  • Spreading viruses and other malware – hackers frequently achieve their goals by spreading viruses and malware. A computer virus, like the biological organism it’s named for, takes up residence in your device’s hardware and software. Like a real virus, it steals resources from your legitimate use of the device and makes the device seem “sick,” i.e. slow or unresponsive. In some cases, a virus will be designed to destroy data in its path or even render a device completely unusable.

    Malware, a related form of malicious software, is usually designed to carry a specific task. It might collect your data and send it off to the hacker. It might spy on your usage habits for a variety of malicious reasons.
  • Ransomware – this is a form of malware that encrypts your files, making them inaccessible to you unless you pay the hacker a ransom. Upon receipt of the ransom, usually demanded in cryptocurrency, the hacker unlocks your files so you can use them again.

  • Cryptojacking – hackers sometimes take over your device so they can use it “mine” for cryptocurrencies like Bitcoin. Cryptocurrency mining is a mathematically intensive process that requires a huge number of CPU cycles. A hacker will embed malware in your system that uses your CPU and network connections to mine for cryptocurrencies.

How do hackers get in?

In order to get malware onto your system, the hacker has to induce you to open a file that contains the malicious code. They accomplish this by sending you files that look legitimate, like Microsoft Office documents or PDFs that contain hidden code that infects your system.

You can also get malware from a USB stick or by visiting a website that loads the code onto your device over the web connection. Sometimes, the hacker has compromised a device somewhere else in the communication chain, like a router, so it can steal your data as it moves across the network.

The Importance of Preventing Hacking

The prevention of hacking is a high priority issue for businesses and government organizations. Data breaches and other destructive cyber incidents can be embarrassing and extremely costly to handle. Individuals should also put effort into preventing becoming victims of hacking.

Hacking is more than just a hassle. Victims of identity fraud, for example, may find themselves dealing with negative impacts on their credit ratings and so forth. Ransomware victims may be unable to work.

Here are the signs that your computer has been hacked

Signs That Your Computer Has Been Hacked

Have I been hacked? Often, it’s hard to know for sure, but there are certain signs that someone has attacked your device. For instance, if you notice unusual activity on your system, you may be a victim of hacker. Let’s say you find software installed, but you don’t remember doing the installation—that’s a classic sign of hacking. Other indicators of hacking include problems like having unknown processes running and high resource utilization.

Seeing your cursor moving on its own or watching words appear on the screen without you typing are also tip offs that your device has been hijacked. Being redirected from the results of an Internet search is another clue. Random pop-ups with false anti-virus messages signify hacking activity.

One of the most common side effects of hacking is a sudden decline in performance. As the hacker’s uses system resources like the CPU, memory and bandwidth, there is less left over for you. Your PC or Mac might be slow to respond to your inputs. It might take forever to boot up. At the same time, you might observe a huge amount of network traffic. Someone’s using your device, just not you.

Random access notifications on social media accounts form another dimension of hacking. Hackers frequently use non-technical means to steal your data. They pose as friends online. They call you and pretend to be from your Internet provider—all to get your system credentials and PII.

What to Do If Your Computer Has Been Hacked

If your computer has been hacked, the best practice is to quarantine it. This may involve the use of anti-virus software, which has quarantine options. Then, you need to run a system scan and root out any malware it finds. Sometimes a basic system cleanse (e.g. CCleaner) can erase malware. If it’s a sophisticated attack, however, you may have to take things a lot further.

Removing a serious system takeover may require completely wiping your hard drive and reinstalling your operating system, but only from a trusted source. With this potential in mind, it’s a wise practice to have a continuous, automated backup in effect through services like Carbonite. That way, if your system has to be erased, your files will still be intact. Then, as you rebuild your system, change your passwords and add two-factor authentication. Check your email and social media accounts to make sure you haven’t accidentally sent malware or fraudulent messages to your friends.

How to Prevent Your Computer from Being Hacked

Preventing your devices from getting hacked is not difficult. There are no absolute protections, but some basic, consistent practices can do a great deal to protect you. One thing that’s essential is to keep your operating system software up to date. With PCs, this is usually automatic. Microsoft issues fixes for security flaws every week.

Strong password practices are another countermeasure. Do not use the same password for every device and app. Keep your accounts secure with a variety of complex password. A strong, complex password is one that contains letters, numbers, capital letters, and symbols like $ and !.

This difference in protection is remarkable when you add more diverse characters. According to, a six-character all lower case password can be cracked in 10 minutes. With the addition of two extra letters and some uppercase letters, that password will now take 3 years to crack. With the addition of characters, numbers and symbols, it takes literally tens of thousands of years to crack.

Change passwords often. And, don’t make a Word document called “passwords” and store it on your machine. That’s the first thing hackers look for. Keep them on paper or secure them with a password manager.

Stay vigilant. Pay attention to what networks you connect to. For example, avoid using public WiFi. You’d be shocked at how easy it is for hackers to read what you’re doing on your machine when you’re on the WiFi at a coffee shop. The nice person at the next table could be a hacker.

Awareness is also your best protection against phishing and scam emails. We all know now to ignore the old “I’m an African prince” emails, but phishers today are infinitely more sophisticated. They might research you on social media and pose as your friends in order to trick you into divulging information.


Hacking is a widespread form of criminal activity. It affects millions of Americans. Hackers usually want to steal your data in order to sell it. Or, they want to steal your computing resources for purposes like mining for cryptocurrency.

Signs that you’ve been hacked include degradation of system performance, odd cursor and text and the appearance of software you didn’t install. It is possible to prevent most hacking by using complex passwords, installing anti-virus software and keeping current on your operating system software. Awareness is crucial. So many attacks arise out of human error. Stay alert and be vigilant about where you store sensitive information, the files you open and links you click. If you are hacked, remediation might involve reinstalling your system software, however. Backups are recommended to preserve files in case of this eventuality.

Hugh Taylor

Hugh Taylor

Hugh Taylor is a Certified Information Security Manager (CISM) who has written about cybersecurity, compliance, and enterprise technology for such clients as Microsoft, IBM, SAP, HPE, Oracle, Google, and Advanced Micro Devices. He has served in executive roles at Microsoft, IBM, and several venture-backed technology startups. Hugh is the author of multiple books about business, security, and technology