What To Do When a Hacker is in Your Computer

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What To Do When a Hacker is in Your Computer

If you discover a hacker is in your computer, disconnect from the internet immediately to stop their access. Notify your IT department or a cybersecurity professional if possible. Check for suspicious activity, such as unauthorized programs or changes, and change your passwords using a secure device. Run a full antivirus and anti-malware scan to detect and remove threats. If issues persist, consider reinstalling your operating system. After regaining control, enable multi-factor authentication, update your software, and monitor your accounts for further suspicious activity. Reporting the incident to the appropriate authorities is also essential to mitigate potential damage.


1. Disconnect from the Internet

The first step is to isolate your computer from the internet to prevent the hacker from continuing to access your system or exfiltrate more data.

  • Unplug the Ethernet cable or turn off Wi-Fi on your device.

  • Avoid reconnecting until you have assessed and addressed the situation.


2. Notify IT Support or a Professional

If the computer is part of a work or organizational network, notify your IT department immediately. For personal devices, contact a trusted cybersecurity professional or support service.

  • Professionals can help identify the scope of the attack and suggest appropriate measures.

Pro Tip: Avoid trying to fix advanced issues on your own, as it may inadvertently make things worse.


3. Identify Suspicious Activity

Look for signs of unauthorized access or changes:

  • Unfamiliar software or files installed on your computer.

  • Changes to system settings, such as altered user accounts or administrative privileges.

  • High CPU or network usage without any clear reason.

  • Pop-ups or ransomware messages demanding payment.

Use tools like Task Manager (Windows) or Activity Monitor (macOS) to check for unusual processes.


4. Change Your Passwords

If you can safely log in to any accounts associated with your computer, change the passwords immediately. Focus on:

  • Email accounts.

  • Banking and financial services.

  • Social media accounts.

Use a Password Manager to create strong, unique passwords for each account.


5. Run Antivirus and Anti-Malware Scans

Perform a comprehensive scan using reputable antivirus and anti-malware tools, such as:

  • Windows Defender (built into Windows).

  • Third-party software like Malwarebytes or Bitdefender.

Ensure your security tools are updated before running scans to detect the latest threats.


6. Remove Unauthorized Software

After identifying malware or suspicious programs, uninstall them immediately. Use:

  • Add/Remove Programs on Windows.

  • Applications Folder on macOS.

For persistent threats, consider using advanced tools like RKill or Safe Mode to remove malicious programs.


7. Check and Reinstall Your Operating System (If Necessary)

If the hacker has gained deep access to your system or if malware persists, reinstalling the operating system may be the safest option.

  • Back up important files first—ensure they are clean and not infected.

  • Use a recovery disk or download a fresh copy of the operating system from the official website.

Pro Tip: Avoid using backups that may have been compromised.


8. Enable Security Measures Post-Breach

After regaining control of your computer, implement these security measures:

  • Enable Multi-Factor Authentication (MFA): Adds a layer of protection for accounts.

  • Update Software and Firmware: Ensure your operating system, browsers, and all apps are patched against known vulnerabilities.

  • Install a Firewall: Activate built-in firewalls like Windows Firewall or use third-party options.


9. Monitor for Ongoing Threats

Stay vigilant for any signs of further hacking attempts:

  • Watch for unfamiliar logins on online accounts.

  • Regularly check your bank and credit card statements.

  • Set up alerts for any suspicious activity on your accounts.


10. Report the Incident

If the hacker accessed sensitive personal or financial information, report the breach to the appropriate authorities:

  • Law Enforcement: File a police report for identity theft or fraud.

  • Your Bank: Notify them immediately to secure your accounts.

  • Federal Trade Commission (FTC): Use IdentityTheft.gov for assistance.

For businesses, comply with any data breach notification laws relevant to your jurisdiction.


When a hacker gains access to your computer, quick and decisive action can significantly reduce the potential damage. Disconnecting your system, assessing the situation, and enlisting professional help are critical steps. By implementing robust security measures and remaining vigilant, you can protect yourself from future attacks and ensure a more secure digital environment.


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