How can you tell if a computer has malware?

1 Slow performance

One of the most obvious indicators of malware is a slow or sluggish computer. Malware can consume a lot of your system resources, such as CPU, memory, disk space, and network bandwidth. This can affect your computer's speed, responsiveness, and stability. If your computer takes a long time to boot, load programs, or perform tasks, you may have malware running in the background.

2 Pop-ups and ads

Another sign of malware is unwanted pop-ups and ads that appear on your screen, browser, or taskbar. Malware can hijack your browser settings, redirect your searches, or install adware that displays annoying or malicious advertisements. These pop-ups and ads can interfere with your work, expose you to phishing or scam sites, or download more malware onto your computer.

3 Unusual activity

Malware can also cause unusual or suspicious activity on your computer, such as changes in your files, settings, or programs. For example, you may notice new icons, toolbars, extensions, or shortcuts that you did not install or authorize. You may also see unexpected messages, errors, or warnings that prompt you to take action or provide information. Additionally, you may observe abnormal network traffic, such as high data usage, connections to unknown servers, or remote access attempts.

4 Antivirus issues

Malware can also affect your antivirus software, which is designed to protect your computer from malicious threats. Malware can disable, delete, or bypass your antivirus, making it ineffective or unreliable. You may notice that your antivirus is not updating, scanning, or detecting malware, or that it is showing false positives or negatives. You may also experience conflicts, crashes, or compatibility issues with your antivirus or other security programs.

5 How to check for malware

If you suspect your computer has malware, you should take immediate action to check and remove it. Windows Security, Malwarebytes, and Command Prompt are all viable tools to scan for malware. Windows Security is the built-in antivirus and anti-malware software for Windows 10, and can be accessed from the Start menu or the taskbar. Malwarebytes is a popular third-party software that can detect and remove various types of malware. Command Prompt is a Windows utility that allows you to execute commands and perform tasks, such as typing tasklist /svc /fi "imagename eq svchost.exe" to check for malware. You can then compare the list with an online database, such as Process Library, to see if there are any suspicious or unknown processes.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?