How to Tell If Your Computer Has Been Hacked and How to Fix It

In today’s digital landscape, Australians are increasingly aware of cybersecurity threats. With estimates suggesting that hackers strike online every 32 seconds globally, it’s crucial for Aussies to stay vigilant about their digital security. While many cyberattacks target businesses and organisations, individual computer users are also at risk of having their personal information compromised.

As cybercriminals continue to evolve their methods, it’s essential to know how to spot potential security breaches on your devices. Whether you’re in Sydney, Melbourne, or the outback, here’s how to tell if your computer has been hacked and what you can do to protect yourself.

How to tell if you’ve been hacked

The first step in identifying a hack is to check your most frequently used and important accounts, such as email, social media profiles, and bank accounts. For instance, have your mates messaged you about a strange DM they received from your account? Or perhaps you’ve noticed an unusual transaction on your bank statement?

These data breaches clearly indicate that a particular account has been compromised. If you notice any suspicious activity, take immediate action. Change your password, notify the company involved, and try to identify the type of cyberattack that occurred to better secure your personal data.

Two most common types of attacks

Let’s examine two of the most prevalent attacks and how to prevent them, both during an active attack and for future protection.

1. Denial-of-service attack

A denial-of-service (DoS) attack often manifests as a sudden, unexplained password change for an account or device. Another sign is the inability to access key system settings, such as factory reset or system restore options. In some cases, a DoS attack may escalate to a ransomware attack, where hackers attempt to hold your sensitive data for ransom.

The best defence against DoS attacks is to follow basic security protocols. These include using strong, unique passwords for each site or using a secure password manager, setting up an internet firewall, and being cautious of email phishing attempts. Here are four additional steps to help prevent a DoS attack:

Check your online account settings

Stay ahead of hackers by regularly reviewing your online accounts for any recent changes. This is especially important for accounts you don’t use frequently or social media profiles you don’t often check. Many social media platforms allow you to secure your account through the account settings if you suspect suspicious activity.

Enable two-factor authentication

Two-factor authentication adds an extra layer of security, making it more challenging for hackers to access your account even if they obtain your password. This feature typically involves your phone number or an authenticator app in the login process, meaning a hacker would need access to your phone as well as the original account. Many major companies, including Google, Facebook, and Twitter, offer this option in their security or help settings.

Check for suspicious logins

Most major online accounts allow you to view login history, including the location or IP address of each login attempt. If you notice an unfamiliar login, immediately change your password and inform the company that your account may have been compromised.

Additionally, remove any credit card or financial information linked to your account settings. This will help prevent further identity theft and ensure your sensitive data remains secure.

Prevent remote access

While remote access is useful in certain work environments, it’s generally unnecessary for personal use. If you don’t have a specific need for remote access, it’s safer to disable it. This helps prevent hackers from accessing your computer remotely and installing malware on your device.

To disable remote access on your PC:

• Click on the Windows Start button
• Type “Allow Remote Assistance invitations to be sent to this computer” in the search bar
• Uncheck the box next to “Allow Remote Assistance connections to this computer”
• Click Apply

To check if someone is remotely accessing your computer without permission:

• Press Ctrl+Alt+Del
• Click on Task Manager
• Review your current processes
• Look for any unusual or suspicious processes or applications

You can also use the Windows Event Viewer app to check for unfamiliar remote access. This app displays a log of application use and system messages, including error messages, with timestamps. If you notice an action at a time when you weren’t using your device, it may indicate unauthorised access. Find this app by searching for “Event Viewer” in the Windows search bar.

2. Suspicious applications installed on your PC

Have you ever discovered programs or applications on your computer that you don’t remember downloading? These are likely malware and could be used for malicious purposes like logging your keystrokes or accessing your online accounts.

If you notice suspicious applications in your list of installed programs, uninstall them immediately. To ensure you can see all applications, start your Windows PC in Safe Mode, then uninstall any suspicious programs to clean up your PC.

Fake antivirus software messages and pop-ups

Malware is often the culprit behind fake antivirus messages and unwanted pop-ups on your PC. If you see random pop-ups on your screen, don’t click them. Instead, close your browser, restart it in incognito mode, and reload the page. Then, check your computer’s antivirus program, firewall, task manager, and registry to ensure they haven’t been disabled or altered.

It’s crucial to only download antivirus software that you’ve thoroughly researched and verified. If something seems illegitimate, it probably is and may introduce malware to your PC.

The dreaded Trojan attack

Fake antivirus software may also serve as a Trojan. Similar to the Trojan Horse of Greek mythology, these attacks allow cybercriminals to bypass your computer’s defences. If you accidentally install a fake antivirus program, your operating system may view it as trusted software. Your OS then won’t prevent you from downloading other malicious programs initiated by the Trojan.

If you fall victim to a Trojan attack, there are steps you can take to mitigate the damage. First, you may need to format your hard drive, which can be problematic if you haven’t backed up your important data. To stay prepared, check out our list of the best Windows backup software for your PC.

If you can’t format your drive, you can combat the threat by downloading a malware removal tool from a non-infected device. Then connect it to your infected system via a USB flash drive. In many cases, this will remove the fake antivirus software without damaging your PC.

Browser toolbars and search redirection

You may occasionally find that your preferred browser loads to an unfamiliar homepage. While this could be an accidental change, it may also indicate a virus that’s actively redirecting your browser. Although there’s no single type of virus responsible for this, it’s important to recognise when your browser has been hijacked and how to restore it to your default or preferred homepage and search engine.

Hackers typically do this to serve you ads or potentially redirect you to a mirror of Google that earns them ad revenue with each search. To resolve this, remove any installed third-party browser add-ons, extensions, and toolbars you don’t recognise.

Also, reset your browser to the default homepage and remove any unwanted search engines from your tools. Then, restart your PC in Safe Mode and ensure the browser works according to your preferences. If issues persist, your system may be infected with deeper malware, requiring an antivirus scan to resolve the problem.

Summary

Staying ahead of hackers isn’t easy, but by following these guidelines, you’ll be better equipped to detect if your computer has been hacked. If you notice anything amiss with your PC, immediately check for changes, especially any programs or applications installed without your consent.

Once you identify the source of the problem on your PC, you should be able to resolve it by following the steps outlined above. Then, take the time to implement some basic cybersecurity measures to prevent future incidents.