Cybersec Essentials

How to know if your computer is hacked

hugh@preyproject.com
Hugh J.
Oct 4, 2024
0 minute read
How to know if your computer is hacked

Cybercriminals are constantly on the lookout for opportunities to infiltrate your devices, access your personal information, and even take control of your digital life. It’s a real concern in today's connected world, and while some hacking attempts can be downright dangerous, others are more of an annoyance—but still not something you want to deal with.

The good news? With the right tools and awareness, you can spot the signs of a hacked computer and take swift action before things get worse. In this guide, we’ll walk you through how to know if your computer has been hacked, the common tactics hackers use, and steps to protect yourself. Whether you’re using a Mac, Windows PC, or even mobile devices like iOS or Android, the threat is real—but so are the solutions.

The harsh reality of data security

Before we dive into the signs of a hacked computer, it’s important to understand the broader context of personal data security. Hackers no longer need to go after you directly—they’re targeting the companies you trust with your personal information. As cybersecurity expert Krebs on Security notes, there are two critical truths we all need to accept:

  1. Your Personal Data is Already Out There: Hackers may already have access to information you assume is private—such as your credit card details, Social Security number, or even your email passwords. These data points often end up on the dark web, thanks to large-scale data breaches.
  2. No Data is Truly Safe: Any personal data you share with businesses or online services will, at some point, be exposed to hackers, leaks, or unauthorized use. Whether it's through breaches, accidental leaks, or the unscrupulous sale of your information, the risks are constant.

How do you know if your computer has been hacked?

If you suspect your computer has been compromised, here are the most telltale signs to watch for:

  1. Unexpected Pop-Ups and Ads: If you suddenly see an influx of pop-ups or ads, especially ones that bypass your browser’s usual ad blocker, this could indicate malware. Hackers use adware to generate revenue, but it also signals deeper vulnerabilities in your system.
  2. Slow Performance and Unusual Behavior: A sudden slowdown in performance, unexplainable crashes, or application freezing can be signs of unauthorized programs running in the background. Hackers often install malicious software to mine data or resources, like cryptocurrency mining, without your knowledge.
  3. Unfamiliar Programs or Files: Check your installed programs or recent downloads. If you notice software or files that you didn’t download or install, your computer could be infected with a trojan or other malicious code.
  4. Changes to Your Settings: Keep an eye out for any changes to your system settings, such as a new homepage, browser toolbars you didn’t add, or security software being disabled. Hackers often modify these settings to maintain control over your device or spy on your activity.
  5. Unusual Activity in Accounts: If you find emails in your outbox that you didn’t send, or strange activity in your online accounts (such as password reset requests or logins from unfamiliar locations), it could be a sign that your computer has been hacked, and your credentials compromised.
  6. Security Software Warnings: Pay attention to alerts from your antivirus or security software. While these warnings aren’t always related to a full system hack, they can flag suspicious activity that could lead to more severe issues if not addressed.

What are the risks of computer hacking?

Computer hacking poses serious risks that go beyond mere inconvenience. Once a hacker gains access to your system, they can steal sensitive personal information such as passwords, financial details, or private documents. This can lead to identity theft, financial fraud, or even unauthorized access to other accounts. 

Beyond that, hackers can install malware, such as ransomware, locking you out of your own files until you pay a ransom. They can also turn your device into part of a botnet, using your computer for illegal activities like sending spam or launching cyberattacks. The financial, legal, and reputational consequences of hacking can be devastating, making it essential to stay vigilant and secure your devices.

Why do computers get hacked?

Hacking is, most of the time, a crime (don't confuse it with Ethical Hacking). 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. Hackers may target your bank accounts to make unauthorized transactions, leading to financial loss.

What to do if your computer is 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. Ensure that your cloud storage accounts are secure and change their passwords as well.

Wipe and Reinstall

Removing a serious system takeover may require completely wiping your hard drive and reinstalling your operating system, but only use 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.

Rebuild Your System

Ass you rebuild your system, change your passwords and add two-factor authentication.

Do a Quick Social Check

Check your email and social media accounts to make sure you haven't accidentally sent malware or fraudulent messages to your friends.

The importance of prevention

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.

Who to call when your computer is hacked?

If you suspect that your computer has been hacked and the situation feels beyond your control, reaching out for professional help is crucial. Start by contacting your IT department if you’re at work, as they can handle security breaches promptly. For personal computers, consider hiring a cybersecurity professional who can assess the damage, remove malware, and secure your system. 

In cases of identity theft or financial fraud, report the incident to your bank or credit card company to prevent further unauthorized activity. Additionally, you may need to file a report with local law enforcement or a cybercrime unit, especially if sensitive information has been stolen. Taking these steps ensures you get expert assistance to contain the breach and recover safely.

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. We'll break them down a bit by operating systems and then provide some blanket tips.

Windows 10 / 11

One thing that’s essential is to keep your operating system software up to date. With PCs, this is usually automatic. Microsoft issues fix security flaws every week.

Windows actually has a security system built into their products. Windows Defender provides basic protection, but it's recommended to use additional security measures for enhanced protection. Windows 10 & 11 have the latest antivirus protection, and also offers 6 other areas of security. You’ll have account protection, firewall, and network protection, app & browser control, device security, performance & health, and family options. They’ve done a great job of updating their systems to provide every possible security.

Macs & Apple computers: Enable Two Factor Authentication

Use a router. If you connect your Mac to a public network (or broadband), it becomes public and is much more vulnerable to being hacked.

Update your system automatically. Apple continually updates its software to prevent hacks before they happen. Along these same lines, you can enable your Mac's firewall.

General Tips

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 passwords. 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 Stopthehacker.com, 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.

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. We recommend using VPN tools whenever you use public wifi.

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 people around the world. 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.

Hopefully, this guide proves helpful as you navigate your way through the cyber world, where hacking is all too prevalent.

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