Computer viruses are sneaky. They’re highly damaging, and most of the time, you don’t even know you have one. Some viruses cause symptoms, but others can slip under the radar. And if you do have one, you need to act quickly.

Often, strange behavior is the result of a virus. If things happen unexpectedly and with no cause, a virus is usually the culprit. Your computer may have a virus if:

  • Your computer is running extremely slowly
  • Programs start up automatically
  • You receive random messages
  • Your modem or hard drive are actively running nonstop
  • You see pop-up ads when your browser is closed
  • You see a message saying you’ve been locked out of your computer
  • Ctrl + Alt + Delete does nothing
  • Your CPU or memory is running high for no reason

 

These behaviors are telltale signs of a malicious virus. They can be tough to spot because it’s easy to think most of these behaviors are only flukes. But it’s better to be safe than sorry.

But these aren’t the worst it gets. Ironically, the worst symptom of a virus is no symptom. Some viruses work deep underneath the surface and affect important parts. Thi  cs can create damage that’s long-lasting and difficult to fix.

Because viruses are tricky to spot, you should run regular virus scans on your PC. If you don’t have an antivirus program, get one immediately! Some great free options include Windows Defender (which ships with Windows 10), AVG AntiVirus Free, and Avast.

If you want to read more about viruses and detection, PC World published two great articles on how to tell if you have a virus and how to remove malware.