Windows Security · Is My PC Hacked? · Lesson 1 of 5

Signs Your PC Was Hacked

Learn which changes point to a real break-in and which are false alarms.

Real warning signs on a PC

Being hacked means someone got into your computer or accounts without your permission. It is scary to wonder about. The good news is that real break-ins usually leave clues you can check yourself.

Look for things that changed when you did not change them. These are the signs that matter most.

• New startup items. A startup app is a program that opens by itself when you sign in. A new one you don't recognize is worth a look.
• Remote access apps you didn't install. A remote access app lets another person see and control your computer over the internet.
• Browser changes. A new home page, a new search engine, or a browser extension you never added. An extension is a small add-on that runs inside your web browser.
• Account alerts. Emails or texts about a sign-in, a password change, or a new device that wasn't you.
• Antivirus turned off. Microsoft Defender Antivirus is the protection built into Windows. Harmful software often tries to switch it off.

One place deserves extra care. AppData is a hidden folder inside your user account where apps keep their files. Many real apps live there, but harmful programs like to hide there too. So check the name and the publisher, which is the company that made the app.

One odd thing alone may have a simple reason. Several together, or one you can't explain, means it is time to clean up.

On the practice computer, work through the checklist. Find the unknown startup item, the remote access app, the strange extension, and the Windows Security history, and remove each one. Then run an offline scan and change your passwords from a clean device.

False alarms that are usually fine

Not every problem means a hacker. Some things feel alarming but have everyday causes. Knowing them saves you worry, money, and calls to fake helpers.

A slow PC is the most common false alarm. Computers slow down for ordinary reasons:

• Too many apps or browser tabs open at once.
• Windows Update working in the background.
• A hard drive that is almost full.
• An older computer running newer, heavier apps.

Restarting often helps. If it stays slow, check Task Manager to see which app is using the most power. Slowness alone is not proof of a break-in.

Pop-up ads on websites are another false alarm. Many free sites are paid by ads, and some are loud and annoying. If the ads only show while you are on one site and stop when you close it, that is the website, not your PC.

Recall from earlier tracks that a fake warning pop-up with a phone number is a scam page, not a sign your PC is infected. Close the tab and never call the number.

Here is a simple test. Ask: did something change that I did not change? A new startup app, a new extension, Defender turned off, or a sign-in alert you didn't cause all point to a real problem. Slowness and website ads usually do not.

Ads that appear everywhere, even on the desktop with no browser open, are different. That points to unwanted software, and the next modules show how to find it.