Think Your Computer Has Malware? The FTC's Warning Signs and Step-by-Step Removal
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How we wrote this: A plain-English summary of the Federal Trade Commission's consumer article on malware, checked October 29, 2026.
Malware is harmful software installed on your device without your knowledge. Viruses, spyware and ransomware are all malware. Criminals use it to steal passwords and bank details, show you unwanted ads, or lock your files and demand payment.
Signs your device may be infected
The FTC lists these symptoms:
- The computer slows down, freezes or crashes.
- Your browser's home page changes or redirects you to sites you didn't choose.
- New toolbars or add-ons appear.
- You see lots of pop-up ads, even on sites that shouldn't have them, such as government sites.
- Repeated error messages from Windows or macOS.
- Task Manager or Activity Monitor is disabled.
- Emails or social posts you didn't write show up.
What to do right away
- Stop logging in to accounts, especially banking and shopping.
- Update your security software, or install some if you don't have any. On Windows, see Windows Security basics.
- Run a full scan to remove the malware.
- From a clean device, change your passwords (see strong passwords) and turn on two-factor authentication (see two-factor authentication).
If you need help, the FTC suggests contacting the device maker (it may be under warranty), a tech support company you know and trust, or a knowledgeable friend.
Never call a number in a pop-up warning. That's a classic tech support scam.
How malware usually gets in
- Phishing links and attachments (see recognize and avoid phishing).
- Fake security warnings that tell you to call for help.
- Software ads on social media and search results. Type the vendor's address yourself.
- Free music, movies or games from unfamiliar sites, and peer-to-peer file sharing.
- Unscanned USB drives.
Prevention
Keep security software updated and set to scan new files automatically. Install updates promptly (see software updates). Keep backups (see 3-2-1 backup) so ransomware can't hold your files hostage.
Report it
Report malware ads, websites or emails, or a ransomware demand, at ReportFraud.ftc.gov. If your personal information was stolen, use IdentityTheft.gov for a recovery plan (see identity theft warning signs).