When a breach is detected, a structured and rapid response is critical to minimizing business impact. This guide outlines the immediate steps your team must take during the crucial first 24 hours of a confirmed security incident.
The first 24 hours of an incident are critical. How you respond determines the scale of the damage and the integrity of the evidence.
1. Containment
- Isolate affected systems from the network. Do not turn them off, as this destroys volatile memory.
- Disable compromised accounts in Active Directory.
- Block known malicious IP addresses and domains at the perimeter.
2. Preservation
- Capture RAM from critical systems immediately.
- Acquire forensically sound images of affected disks.
- Preserve central logs (SIEM, firewall, VPN, domain controllers).