Shutdown NOW! — Immediate Actions for Cybersecurity Emergencies
Purpose: Rapid, prioritized steps to stop active cyber incidents, limit damage, and preserve evidence.
Immediate (first 0–15 minutes)
- Isolate affected systems
- Disconnect compromised machines from the network (unplug Ethernet or disable Wi‑Fi).
- Cut external access
- Block external IPs, shut down VPN gateways, and disable remote access (RDP/SSH) to stop attacker control.
- Preserve volatile evidence
- Capture memory and active network connections if you have trained staff/tools; if not, power down after documenting state (screenshots, running processes).
- Activate incident response
- Notify your incident response lead and pull the IR playbook. Assign roles: containment, analysis, communications.
- Stop ongoing spread
- Quarantine related systems and suspend automated deployments, backups to external sites, and syncs that could propagate malware.
Short term (15 minutes–4 hours)
- Assess scope
- Identify affected hosts, user accounts, services, and potential data exfiltration channels.
- Collect logs
- Secure logs (SIEM, firewall, endpoint) and network captures to a safe repository for analysis.
- Revoke/rotate credentials
- Disable compromised accounts and rotate credentials and keys with high risk of exposure.
- Apply temporary mitigations
- Patch known exploited vulnerabilities, apply firewall rules, and deploy endpoint containment policies.
Recovery (4 hours–days)
- Eradicate root cause
- Remove malware, close exploited vulnerabilities, and rebuild compromised systems from known-good images.
- Restore services safely
- Bring systems back in a staged manner behind monitoring and strict access controls.
- Validate integrity
- Scan and verify rebuilt systems; confirm no persistence mechanisms remain.
Communication & compliance
- Internal: Give concise status updates to leadership and affected teams.
- External: Follow legal/contractual requirements for breach notification and prepare statements for customers and regulators.
- Forensics: Engage forensics if attribution, legal action, or regulatory evidence is needed.
Post-incident actions
- Conduct a root-cause analysis and update IR plans, playbooks, and detection rules.
- Run tabletop exercises to test improvements and train staff.
Quick checklist (for responders)
- Isolate → Block external access → Preserve evidence → Notify IR lead → Quarantine → Collect logs → Revoke creds → Patch/mitigate → Rebuild → Communicate.
If you want, I can convert this into a printable one‑page checklist, a playbook with command examples (iptables, netsh, firewall rules, memory capture tools), or tailor steps for cloud environments (AWS/Azure/GCP).