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How to tell if your PC has been hacked

PC Performance
PC Performance

The internet is a massive, wonderful place that has changed the way we live. While most of us go about our business without thinking of harming anyone else, others would like nothing more than to infect your Windows 10 PC with malware or hack their way into your life to steal sensitive information. If you think you might be in trouble, have a look at these telltale signs, as well as some things you can do about them.

How to tell if you've been hacked

While we won't get into the nitty-gritty of cybersecurity, it's good to keep these signs in mind. If you're experiencing any of these issues, there's likely some form of malware on your PC, or your accounts have been compromised.

You're sending friends spam email

No one likes receiving spam, especially if it's from a close friend or colleague. You might not notice that there are a ton of messages going out, but if someone tells you that you're bombarding them with spam, your PC is likely compromised. Let them know that they should not open any messages from you for the time being, and they shouldn't click any links.

You're locked out of your user accounts

Whether online or local, finding that you're locked out of your user accounts is a big sign that you've been compromised. This most likely has to do with a phishing scheme, where someone spoofs a legitimate service to get your credentials. With the case of online accounts, notify the service and let them know that you believe you've been hacked. You'll also want to change all of your other passwords, because they could have been compromised, as well.

If you notice that your local passwords have changed, it's time to run your antivirus software and hope it can catch whatever's infecting your PC.

Your antivirus is no longer running

Did Windows Defender or whatever third-party antivirus you use stop running on its own? Check for any issues (like an update being seriously required), but know that this is usually a clear sign that your PC has been infected. Likewise, if you can't get into your Task Manager, you know it's time to get busy removing the malware.

Your PC has new software installed

Are you noticing some weird programs in Task Manager that run when your PC boots? Do they often hog resources? Do they frequently request permission to pass through your firewall? These programs might have been included with other software you downloaded and might installed secretly when you installed something else.

If you're suspicious that some programs running on your PC shouldn't be there, check out Microsoft's Process Explorer (opens in new tab) to see exactly what each program is doing and why it's running in the first place.

You're seeing malicious pop-ups

One of the most horrifying views you can have on a PC is a browser that's absolutely jam-packed with extra toolbars. While the major browsers have done a decent job of weeding out the worst offenders, a lot still get through, especially on PCs with users who don't understand the danger.

If you're constantly seeing shady pop-ups while browsing, or you're being redirected to strange websites when clicking links, check to see if your browser has extra toolbars installed that you don't remember adding. Remove them, run your antimalware software, and test things out.

Your PC has slowed to a halt

Has your PC lost some of its legs? Does it take forever to boot Windows and load programs? Are you ready to tear your hair out? A PC taking a serious hit to performance in a short amount of time usually means it's busy doing other things, like serving the malware that's infecting it.

You can try these tips for boosting performance, but if the decline was seemingly overnight, you're likely dealing with a larger issue.

Your network activity has gone through the roof

This is a problem that's especially damaging for anyone on a metered internet connection. No one wants to go over their data limit, but malware could not care less. If you receive an alert from your ISP that your network activity has exceeded its limit and you know you didn't do anything out of the ordinary, your PC is likely working for someone else.

Use our guide to managing wireless networks to monitor and determine whether or not your PC is making malicious connections.

Your social media accounts are posting on their own

Has your Facebook account been especially active lately? Have you not personally logged in in weeks? Similar to the spam email problem, your friends on social media services might be seeing you post malicious links or strange advertising.

If you get a heads-up that your account is doing things that you didn't know of, you'll want to change your passwords and let people know to ignore any messages or requests for the time being. It's also important to reach out to the service to let them know that your account has been compromised.

Your mouse cursor is doing its own thing

If your mouse cursor is seen moving around your display, clicking on programs or links, things are probably pretty bad. Your PC is likely being controlled remotely, and at that point, it's time to burn it with fire. Or at least perform a complete reset of Windows. Hope you have some backups handy!

What to do if you've been hacked

Most of the above signs — unless only a certain account was compromised in a phishing scheme — mean it's time to either remove malware with software or completely reset your PC using backups, to get to a point before the infection occurred.

There are already plenty of articles written on Windows Central that can not only help you deal with removing malware, but also help you prevent it from ever happening.

Prevention

Removal

Recovery

Cale Hunt
Senior Editor, Laptop Reviews

Cale Hunt is a Senior Editor at Windows Central. He focuses mainly on laptop reviews, news, and accessory coverage. He's been reviewing laptops and accessories full time since 2016, with hundreds of reviews published for Windows Central. He is an avid PC gamer and multi-platform user, and spends most of his time either tinkering with or writing about tech.

24 Comments
  • You can actually sniff it. If your PC starts smelling like rotten eggs you have a virus. The only thing left is bringing your old buddy in the backyard and shoot him right into the screen. Everything else in inhuman.
    Trust me. I've studied PCs in their natural habitat for years. It's really sad when one of these poor little netbooks get a virus and the mother tower PC just let them die. Nature is beautiful but brutal.
  • A tech guru who I once knew taught me a foolproof way to diagnose whether a PC had been hacked: see if it is running Windows.   If so, presume the worst.   ;-)
  • That's not hacked, that's infected with viruses. =P
  • When you repeat an old boring joke at least do it right.
  • Kung Fury for the win!!!
  • I see a lot of those popups. Just not on my PC. I see them especially when I visit this site on any iOS device. Maybe those iMore guys could do an article on how to get rid of that. It seems that I'm always winning $1000 dollar gift cards. 
  • Get a Mac
  • I really hope that's a joke lol.
  • It's just a same. Mac can get viruses and malwares. Can hacked it too.
  • You're kidding, right?
  • I'd like some fries with that : - ) "virus free" the lie of a lifetime, gotta hand it to steve job's marketing skills and the bunch of buffoons who bought into that, least we know that people who are capable of that much stupidity/ignorance exist in this world and time.
  • Well yea they all bought iphones you know the 2 year old technology today device.
  • The first sign is a giant skull and crossbones filling the screen accompanied by a deep laughter.
  • This is so sad...☹️
  • But can be happy if we solve it.
  • Been using Windows since Windows 95 was available, never been hacked. I'm not stupid enough to click on any dodgy links or visit dubious websites. Common sense is better than any AV software.
  • Doggy links? Oh I know what you mean 😏
  • If you constantly back up files like I do, I usually just wipe windows completely without recovering any files. Always better to start fresh.
    I also wipe everything every 3 months.
  • I now store files on the cloud, use SVN and use web-based app / services (e.g. Netflix). Need no backup if you store nothing locally.
  • Get Linux!
  • And once again just as vulnerable
  • But not targeted, same as Macs
  • Only ever had the Sasser virus and that was XP days
  • It's also quite possible to not notice any of the above if you've TRULY been hacked. The only things that would give the hack away would probably be the empty bank accounts, crypto wallets and your nude pics posted online.