Signs of infected Computer

11 Signs Your Computer May Be Infected With Malware

 By Charles Joseph | Cybersecurity Advocate
 Last update: November 25, 2023

A malware infection can manifest in various ways, depending on the type and purpose of the malicious software.

11 Signs Your Computer May Be Infected With Malware

1. Slower Performance

A sudden or gradual decrease in your computer’s performance, such as a slow startup, slow application loading, or overall sluggishness, could indicate a malware infection.

2. Frequent Crashes or Freezes

Unexplained system crashes or freezes may be a sign that malware is interfering with your computer’s normal operation.

3. Unusual Network Activity

Unexpectedly high network activity, even when you’re not actively using the internet, could suggest that malware is communicating with a remote server or participating in a botnet.

Stay One Step Ahead of Cyber Threats

Want to Be the Smartest Guy in the Room? Get the Latest Cybersecurity News and Insights.
We respect your privacy and you can unsubscribe anytime.

4. Unexpected Pop-Ups or Ads

An increase in pop-up ads or unexpected browser redirects, especially to suspicious websites, might be a sign of adware or other malware.

5. Unfamiliar Programs or Icons

If you notice unfamiliar programs or icons on your computer that you don’t remember installing, it’s possible that malware has been installed without your knowledge.

6. Disabled Security Software

Malware often attempts to disable antivirus software, firewalls, or other security measures to avoid detection and removal.

7. Unusual System Messages or Errors

Unexpected error messages or system notifications, particularly those that mention missing or corrupted files, could indicate a malware infection.

8. Browser Homepage or Search Engine Changes

If your browser’s homepage or default search engine has been changed without your consent, it might be a sign of a browser hijacker or other malware.

9. Suspicious Emails or Social Media Messages

If your contacts receive unexpected emails or social media messages from your accounts, it could be a sign that your computer is infected and being used to spread malware or phishing attempts.

10. Unauthorized Access to Accounts

Unexplained changes to your online accounts or unauthorized access could suggest that malware has stolen your login credentials.

11. Increased CPU or Memory Usage

A sudden spike in CPU or memory usage, even when your computer is idle or running minimal tasks, could indicate that malware is consuming your system resources.


If you notice any of these signs, it’s essential to take action immediately to mitigate the potential damage.

Scan your computer with reputable antivirus software, remove any detected malware, and follow best practices for securing your devices and accounts to prevent future infections.

5 Signs Your Computer Has Been Hacked (Video)

"Amateurs hack systems, professionals hack people."
-- Bruce Schneier, a renown computer security professional