Incident Response and Threat Hunting in Action

Incident response and threat hunting are two essential activities in modern security. When a suspicious event appears, the IR team acts fast to limit damage, while threat hunters search for hidden adversaries and the underlying plan. Together they create a loop of detection, investigation, and improvement.

A practical IR playbook helps teams act consistently: define the scope, identify impacted assets, contain the spread, eradicate the threat, recover operations, and conduct a lessons-learned review. This structure keeps teams coordinated under pressure and allows for faster decision making.

Triage and containment

  • Confirm the alert is real and assess its severity.
  • Map affected devices, users, and networks to see the spread.
  • Preserve evidence and maintain chain of custody for investigations.
  • Isolate compromised hosts or segment networks to stop further damage.
  • Revoke or reset credentials for affected accounts and enforce stronger controls.

Evidence collection and forensics

  • Gather logs from SIEM, EDR, firewall, and endpoints; seize memory if feasible.
  • Build a clear timeline using accurate clocks and cross-system events.
  • Hash key files and tag artifacts to guide root-cause analysis and reporting.

Threat hunting techniques

  • Start with a hypothesis: what attacker goal fits the signals you see?
  • Use MITRE ATT&CK as a map for techniques like credential access or lateral movement.
  • Check threat intel for known IOCs and campaigns that match your environment.
  • Look for beaconing patterns, unusual logon bursts, or unexpected admin activity.

Example scenario

A phishing email leads a user to a malware link. The network shows a sudden outbound connection from a single host. Hunters hypothesize initial access followed by beaconing. The IR team quarantines the device, collects a memory dump and disk image, and traces the attacker’s steps to block the same method elsewhere.

Collaboration and learning

Security runs best when IR, IT, legal, and compliance work together. Clear communication speeds containment, while a post-incident review turns findings into improved tools, rules, and training. Documentation helps teams respond better next time.

Automation and playbooks

Runbooks automate repetitive tasks like evidence collection, alert triage, and evidence tagging. Mapping steps to MITRE techniques keeps every action aligned with a known framework, making audits easier and recovery smoother.

Key Takeaways

  • Threat hunting uncovers what IR alone might miss.
  • A strong, repeatable playbook reduces response time and errors.
  • Documentation and after-action reviews continually improve defenses.