Skip to main content
  1. Home
  2. Computing
  3. Legacy Archives

Six signs your computer is infected

Add as a preferred source on Google
Computer Virus Detected
Image used with permission by copyright holder

Viruses – both real and virtual – have a lot in common. For starters, they both suck to catch. Smallpox, Stuxnet, Conficker, or the common cold – we can all agree that regardless of whether they’re in your body or your PC, viruses are universally awful. Second of all, while both types of viruses can be avoided with the proper precautions, odds are you’ll still pick one up at some point in your life. And lastly, just like recognizing a viral infection in your body, knowing if your PC has been infected is all about knowing the symptoms. So, as netizens concerned for the well-being of the community, we’ve put together this list of computer virus symptoms to help you diagnose any problems you might be experiencing.

Telltale signs of an infected PC

Pop-up ads

Remember these things? Dear god were they annoying back in the day. One minute you’re minding your own business, talking with your buddy through this newfangled online chatroom thingy, and then BAM! a flashy window appears to inform you that you’re millionth visitor to this site, and you absolutely must CLICK HERE TO CLAIM YOUR PRIZE! 

Virus hit page counter

Luckily, those days are behind us. Most modern browsers now include robust popup blockers, so pop-ups shouldn’t really be a problem anymore if your browser is up to date. The occasional pop up might still happen if you’re clicking around a shady site, but it’s highly unlikely nowadays that you’ll encounter a lot of them online. If you’re getting a lot of pop-ups while you’re surfing the Web, it’s likely just a poorly-configured browser. Adjust your settings and they should go away.

Recommended Videos

What you should really worry about is if you’re still getting pop-ups while your browser isn’t even open. If that’s the case, chances are good that you have a virus on your system. The most common ones are ads that say something like “Alert! your computer might be infected with a virus,” and then offer up free software to fix it. Please don’t be a numbskull and fall for this – you’ll only be downloading more malware.

To get rid of the virus, get your hands on a malware removal tool. We recommend using Spybot Search & Destroy (free) or Malwarebytes Virus Removal ($25).

Hijacked accounts and messages you didn’t send

Just like real-world viruses, computer viruses are on a mission to spread and infect as many machines as possible, and often they way they do this is by hijacking your email, IM, or social media accounts and sending malware-laden messages to your contacts. This is hard to detect sometimes, since most of us keep a close watch on our inboxes, but rarely stop to check our outboxes. More often than than not, you find out about these phantom messages from your savvy friends who see them in their inbox, realize something’s phishy, and let you know you might’ve been hacked. Just keep an eye on your Sent messages on every platform and make sure you change your account password if you notice anything you didn’t write yourself.

Lockdown warnings

So you’re on your PC, doing your thing and putting the finishing touches on the most adorable kitten GIF of all time. Suddenly, an official-looking message appears on your screen, informing you that your computer has been locked due to your illegal activity, and that you must pay a fee to regain control of it. Don’t worry, these types of messages are complete bullshit. You weren’t doing anything illegal – kitten GIFs are not illegal! –  your computer is just infected with ransomware.

Ransomware
Image used with permission by copyright holder

Sometimes these messages aren’t even official-looking; they’re just plain old ransom notes that say, “we’ve taken control of your computer, pay us and we’ll let it go free.” Whatever you do, do not enter any kind of payment information. Chances are slim that it’ll give you back control. What’s worse is that you probably won’t be able to remove the virus with your normal antivirus software either – you’ll need to get your hands on a rescue disc from AVG or Kaspersky.

Crashing, freezing, and general slowness

While system crashes, frozen screens, and painfully slow operation could be caused by poor configuration, these can sometimes also indicate that your PC is infected with malware. The best way to tell if it’s one or the other is how quickly things got bad. If your computer has gradually been getting slower over time and has now reached a point where it occasionally comes to a halt, it might be simply because you haven’t been performing regular system maintenance. Check out our guide to speeding up your PC to help speed things back up.

If your computer was running smoothly one day, and suddenly became laggy, slow, and unresponsive overnight, then there’s a chance that malicious software is the cause. Viruses often run tasks that take up a lot of resources and make your system run more slowly than usual. Try opening up Task Manager to see what’s running. If that doesn’t work, keep reading. 

Essential functions don’t work

Most major operating systems come standard with a task manager that allows you to see what your PC is doing at any given moment. For Windows users, this can be accessed with control+alt+delete, whereas Mac users can simply open Spotlight (command+space) to find/open the Activity Monitor program. These tools will provide you insight into what programs are currently running on your computer, and you should always be able to access them. If for some reason you can’t get your task manager (or other diagnostic tools) to open, there’s a chance your computer is infected with a virus that doesn’t want you to find it.

If this happens, run your antivirus program if you can. If you can’t (presumably because the virus is blocking this too), then you’ll likely have to resort to a separate virus removal tool. 

Nothing’s wrong

Even if everything seems peachy and your computer runs without any problems, there’s always the chance that your system is harboring a malicious piece of software that you’re totally unaware of. As a general rule, the more advanced the virus, the lower your likelihood of discovering the infection. Think about it – if you were a world-class cybercriminal, would you design a virus that people could easily detect and shut down, or would you take time to make it practically invisible? Exactly. 

Some of the most sophisticated viruses in the world have been found to include software that actually deletes other malicious files that might get cause virus scanners to send up red flags. As cybercriminals continue to step up their game, it’s increasingly likely that you won’t even notice your computer has a virus, so keeping this in mind, you shouldn’t always assume that you aren’t infected simply because your system runs smoothly. At the end of the day, the best way to keep your PC malware-free is to give it regular checkups with a good antivirus program, and always make sure that your operating system is up to date.

Looking for a good antivirus program that won’t break the bank? Check out our lists for the best free antivirus sofware, and the best free antivirus software for Mac OS X.

Drew Prindle
Former Senior Editor, Features
Drew Prindle is an award-winning writer, editor, and storyteller who currently serves as Senior Features Editor for Digital…
Amazon wants to design in-house chips for Kindles, Fire TV, and Echo speakers
Apple did it first. Amazon is doing it now, starting with 40 million chips a year and a partner most people have never heard of.
Amazon Kindle Scribe dark mode featured image.

Apple's decision to design its own chips reshaped the consumer electronics industry. Amazon may be about to make the same call, just about two decades later.

Supply chain analyst Ming-Chi Kuo reports that Amazon is preparing to shift away from externally sourced processors for its consumer electronics lineup, marking what he describes as the company's first major processor procurement change in 20 years. The transition is expected to begin in 2027.

Read more
AI wants to summarize it all. TripAdvisor’s misleading reviews show AI will also ruin your travel plans
Spotless, friendly, and totally wrong. AI summaries are hiding the reviews that actually matter.
Tripadvisor logo on MacBook

Planning a trip is stressful enough without wondering if the glowing hotel summary you just read was written by an AI that skipped the scary parts. As it turns out, that might be exactly what's happening on TripAdvisor.

According to an investigation by consumer group Which?, reported by the Guardian, TripAdvisor's AI-generated review summaries are smoothing over serious guest complaints, and in some cases, downright dangerous ones.

Read more
Opera’s new Paste Protect feature stops the clipboard attack your antivirus can’t catch
ClickFix attacks trick you into compromising your own device, and no major browser had a native defense against them until now.
Opera Paste Protect featured

Most online scams are easy enough to spot once you know what to look for. Fake login pages, suspicious attachments, or urgent wire transfer requests are dead giveaways. But ClickFix doesn't look like any of them. It presents itself as a solution, and it asks you to do something so routine that few people think twice about it.

The technique was behind more than 53 percent of malware loader incidents last year, according to cybersecurity firm Huntress, and no major browser had a native defense against it until now. Opera is fixing that with a new feature called Paste Protect.

Read more