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

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

Daniel Horowitz
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Reading time: 7 minutes
There is no doubt that hacking and cybercrime are on the rise. In fact, it is estimated that hackers attack someone online every 32 seconds. While many of them target companies and organizations, others go after private individuals in an attempt to steal personal information from computers, cell phones, and tablets.
While cybercriminals will continue to find new methods to infiltrate your devices, there are ways to remain vigilant and aware of your computer’s security status. No one is asking to be hacked, of course, but it’s an unfortunate reality for everyone. And if this happens to you, here’s how to tell if your computer has been hacked and how to stop hackers in their tracks.

How to tell if you've been hacked

The first way to tell if you've been hacked is to check your most used and vital accounts, like your email addresses, social networking profiles, and bank accounts. For example, have your friends and family tweeted or texted you about a weird DM you sent them? Or maybe you noticed a suspicious charge on one of your bank accounts.
These data breaches will make it very clear that a particular account was hacked. If you notice any suspicious activity like this, take immediate action. Change your password, notify the company, and try to identify the type of cyberattack that occurred so you can secure your personal data.

Two most common types of attacks

Now, let’s take a look at two of the most common attacks and how to stop them, both while they’re happening and in the future.
Person Hacking on Laptop

1. Denial-of-service attack

You can tell that a denial-of-service (DoS) attack occurred when your password seems to have randomly changed for an account or device. Another indicator is if you can no longer access key system settings, such as a factory reset or system restore option. A DoS attack can sometimes culminate in a ransomware attack, which means a hacker will attempt to hold your sensitive stolen data ransom.
The easiest way to avoid DoS attacks is to follow basic security protocols. These include using a strong, unique password on every site or using a secure password manager, setting up an internet firewall, and avoiding any email phishing attempts. Beyond those basic tips, let’s look at 4 additional steps you can take to prevent a DoS attack.

Check your online account settings

You can stay ahead of hackers by keeping an eye on your online accounts to see if there are any recent changes. It’s easy to overlook this step, especially if you don’t use a particular account often or you don’t look at your own page frequently, in Facebook for example. It’s worth doing, though, because social media sites allow you to lock down your account in your account settings tab if you’re worried about suspicious activity.

Enable two-factor authentication

Two-factor authentication makes it more difficult for hackers to access your account and adds another layer of security, even if someone steals your password. This adds your phone number or an authenticator app to your log-in process, which means the hacker would need access to your phone as well as the original account. Many major companies offer this option, including Amazon, Google, Twitter, and Facebook, within their security or help settings.

Check for suspicious logins

Most major online accounts will allow you to see when someone has logged into your account and from what location or IP address (click here to learn how to find your IP address). If you do not recognize the login attempt, then you should immediately change your password and notify the company that your account was compromised.
Also, disconnect any credit cards or other financial information tied to your account settings. This will help prevent further identity theft and ensure that your sensitive data does not fall into the wrong hands.

Prevent remote access

Remote access is a great feature for certain industries and employers, because it helps to connect employees to necessary servers and storage devices via their internet connection. Beyond workplace settings, however, there are limited cases in which you would want to access your device remotely.
If you don’t have a good reason to use remote access, it’s more secure to turn it off. This helps prevent hackers from accessing your computer remotely, which prevents them from installing malware on your device remotely.
To prevent remote access to your PC:
  • Click on the Windows Start button
  • Type in "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
If you want to know how to check whether someone is remotely accessing your computer without your permission, follow these steps:
  • Press Ctrl+Alt+Del
  • Click on Task Manager
  • Review your current processes
  • Identify if there are any processes or applications that look unusual or suspicious
Another option is to check the Windows Event Viewer app to look for any unfamiliar remote access. This app shows a log of application use and system messages, including error messages, with timestamps. If you don’t recognize a particular action at a time that you were on your device, then it is likely that someone accessed your PC. You can find this app in the Windows search bar by searching for "Event Viewer."

2. Suspicious applications installed on your PC

Have you ever found programs or applications installed on your computer that you don't remember downloading? Chances are they’re malware and someone may be using them for nefarious purposes like logging your keystrokes or getting into your online accounts.
If you do notice suspicious applications in your list of installed programs, it’s imperative that you uninstall them immediately. And to make sure you can see every possible application, 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 at the root of fake antivirus messages and other unwanted pop-ups on your PC. If you see random pop-ups on your screen, do not click them. Instead, close your browser and start it again in incognito mode and reload the page. Then, check your computer’s antivirus program, firewall, task manager, and registry to make sure they’re not disabled or altered in any way.
It’s important to never download any antivirus software that you have not thoroughly researched and vetted. If it seems illegitimate, it probably is, and it may lead to malware landing on your PC.
Virus Popup on Computer

The dreaded Trojan attack

Fake antivirus software may also serve as a Trojan. Much like the Trojan Horse of Homer’s Iliad, these attacks allow bad actors to rush through the gate of your computer. If you installed a fake antivirus program by mistake, your operating system may view it as a trusted program. Your OS then won’t stop you from downloading anything else nefarious initiated by the Trojan.
If you fall victim to a Trojan attack, there are steps you can take to mitigate it. First, you need to format your hard drive, which may be painful if you haven’t backed up your important data. For those who may not be up to date with this critical maintenance task, check out our list of the best Windows backup software to be prepared.
If you can’t format your drive, you can stop 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

There may be times when your browser of choice inexplicably loads to a homepage you’ve never seen before. If you made this change by accident, it’s easy to fix. But it may actually be a sign that you’re the victim of a virus that is actively redirecting your browser. There is no single type of virus that performs this function, but it’s important to know when your browser is hijacked and how to clear it back to your default/preferred homepage and search engine.
Hackers typically do this as a way to serve you ads. They may even potentially redirect you to a mirror of Google that earns them ad revenue every time you search. To get rid of this, remove any installed third-party browser add-ons, extensions, and toolbars you don’t recognize.
You should also change your browser back to the default homepage and remove any unwanted search engines from your tools. Then, restart your PC in Safe Mode and make sure the browser works according to your preferences. If not, your system is likely infected with deeper malware and you will need to run an antivirus scan to fix the issue.

Summary

Staying ahead of hackers isn’t easy, but by following what we’ve outlined, you will know how to tell if your computer has been hacked. If you notice anything wrong with your PC, immediately check for things that have changed, especially whether any programs or applications were installed without your consent.
Once you identify what is causing the problem on your PC, you should be able to solve it by troubleshooting the issue with the steps above. Then, take the time to put some basic cybersecurity measures in place so it doesn’t happen again.
About the Author: Daniel Horowitz is a contributing writer for HP Tech Takes. Daniel is a New York-based author and has written for publications such as USA Today, Digital Trends, Unwinnable Magazine, and many other media outlets.

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