What To Do if Your Computer is Highjacked by Ransomware

What to Do If Your Computer Is Compromised by Ransomware | Step-by-Step Recovery Guide

What to Do If You Think Your Computer Security Is Compromised by Ransomware

Updated October 16, 2025 • Category: Cybersecurity / Threat Response

Ransomware is malicious software that encrypts your files or locks you out of your system, then demands payment—usually in cryptocurrency—to restore access. Beyond encryption, some variants also steal data and threaten to publish it online—known as double extortion. Because ransomware uses strong encryption, recovering without the decryption key is nearly impossible. That’s why fast, informed action is vital.

🔍 How to Tell If You’ve Been Infected

SignWhat It Means
Files won’t open or show new extensions (.locked, .crypt)Likely ransomware encryption
A ransom message appearsAttackers are demanding payment
PC slows down or crashesEncryption process running
Antivirus disabled or missingMalware interference
Network traffic spikesPossible data exfiltration

✅ What to Do Immediately

1) Disconnect from All Networks

Unplug Ethernet and disable Wi‑Fi to stop the spread to other systems or drives.

2) Document the Attack

Screenshot ransom messages, filenames, and timestamps. Keep evidence for law enforcement or cyber insurance.

3) Alert Experts

Notify your IT provider or security partner. In the U.S., also report to the FBI Internet Crime Complaint Center (IC3).

4) Identify the Ransomware Type

Use NoMoreRansom.org to check for free decryptors.

5) Remove the Malware

Use trusted tools (e.g., Bitdefender, Malwarebytes, ESET) to eliminate the malicious payload.

6) Restore Clean Backups

Only restore from offline or immutable backups after confirming the environment is clean.

7) Rebuild Securely

Reinstall the OS if needed, patch fully, rotate credentials, and enable MFA everywhere.

🚫 What NOT to Do

  • Don’t pay the ransom unless absolutely necessary—there’s no guarantee of recovery.
  • Don’t reconnect infected devices to your network.
  • Don’t restore from unverified backups.
  • Don’t skip reporting and documentation.
  • Don’t panic—follow a plan.

🧰 Prevention Tips

  • Keep operating systems, apps, and firmware updated.
  • Use real-time antivirus and firewalls.
  • Train users to recognize phishing and malicious attachments.
  • Implement network segmentation and least-privilege access.
  • Maintain offline backups and test recovery regularly.
  • Enable MFA everywhere.
Need help now? Contact your incident response partner and report to IC3. Time is critical.