Malware Analysis for Incident Responders
Malware analysis is a practical skill set for incident responders. It helps confirm what happened, maps the attacker’s steps, and guides the cleanup. A steady, repeatable workflow keeps findings clear and shareable across teams.
Triage and evidence collection are the first steps. Isolate the affected host to stop spread, then preserve memory dumps, disk images, logs, and configuration files. Maintain a simple chain of custody: date, who collected, and where it’s stored. Document every observation as you go.
Static analysis looks inside the file without running it. Check the file type and header, study imports and strings, and note any obfuscated code or packers. This can reveal the malware family and built-in capabilities, such as credential theft or lateral movement.
Dynamic analysis lets the software run in a safe environment. Observe file system changes, process creation, and network calls. Watch for new executables, scheduled tasks, or suspicious child processes. Capture network artifacts like domains, IPs, and beacon patterns, but do not interact with live systems beyond the sandbox.
Memory forensics helps when the sample is already active in memory. A RAM image can show loaded modules, hidden processes, and pointed-to network connections. Look for unusual DLLs, code injection, or reflective loading that might bypass protections.
From these steps, extract IOCs: file hashes, domain names, IP addresses, registry or service changes, and unique mutexes. YARA rules are useful to detect similar threats in the future. Keep rules simple at first and expand as you learn more about the malware family.
Containment and eradication follow. Patch exploited flaws, revoke compromised credentials, and block known C2 domains or URLs. Restore systems from trusted backups, then monitor for re-infection. Share a clear incident report with timelines, evidence lists, IOCs, and recommended actions.
Example scenario helps tie it together. An employee clicks a phishing email and runs a downloader. Collect sample, perform static analysis to spot a downloader payload, run dynamic analysis to observe outbound connections to a suspicious host, and check memory for injected processes. Record the hash, domains, and network patterns, then implement defense changes and a post-incident review.
Key Takeaways
- A structured workflow improves accuracy and communication during malware incidents.
- Combine triage, static and dynamic analysis, and memory forensics for a full view.
- Create clear IOCs and actionable steps to contain the threat and prevent recurrence.