If you suspect that your computer is infected with malware, it’s essential to take immediate action to secure your data. Here are the steps to follow:
Disconnecting from the Internet immediately is the first step in removing malware. This prevents further spread and communication with remote servers.
Next, boot your Windows PC into Safe Mode, which runs the system with minimal resources and only necessary drivers. This helps prevent the malware from spreading and interfering with antivirus scans or corrective actions.
Run a full system scan with Windows Defender to detect any quarantined or deleted threats, followed by a second scan with a third-party antivirus like Malwarebytes to check all files, programs, and processes for signs of malware. Ensure your antivirus tool is up-to-date.
Check for unusual installed programs that may have been installed without your knowledge. Review the list of installed apps in the Settings app, and remove any suspicious programs.
Malware can also hijack system resources, such as CPU or disk space, to run resource-intensive operations. Use the Task Manager to identify any suspicious activity and delete malicious files if necessary.
Inspecting startup apps can help you identify any malicious software running without your knowledge. Review the Startup tab in the Task Manager and disable any unfamiliar or suspicious apps.
The Task Scheduler can also be used to identify malicious tasks that may still be being executed in the background. Review the Active Tasks list and delete any tasks you don’t recognize.
It’s also essential to verify that no threat actor has established a remote connection to your computer and is monitoring you. Check for active connections using Command Prompt, review network connections, and disconnect any suspicious IP addresses.
Finally, check your browser for signs of infection, such as unfamiliar extensions or redirections. Remove any suspicious extensions, change your default search engine, clear cookies and cache, and delete the browser app if necessary.
Source: https://www.howtogeek.com/steps-to-take-if-you-accidentally-download-malware-on-windows/