Malware Analysis: From Static to Behavioral

Malware analysis helps security teams understand threats at two levels. Static analysis looks at the sample itself, without running it. It asks what type of file it is, what components it includes, and how it is built. Behavioral analysis watches the program in a safe, controlled environment to see what it does, such as network calls, file changes, and new processes. Together, these angles give a fuller picture.

Static Analysis

Begin with identification and surface clues. Check the file type, header structure, and packing. Look for strings that reveal commands, domains, or filenames. Review the import table and API calls to guess what the program might try to do. High entropy, unusual sections, or packed code often signal concealment. Tools like hash calculators, basic disassemblers, and heuristic viewers help you form a hypothesis before any execution.

Behavioral Analysis

In a sandbox, observe real actions: does the sample reach out to a remote server, write to user folders, or create new processes? Monitor system calls, registry changes, and network traffic. Common findings include dropped payloads, mutexes, or unusual process trees. Use logging and automation with tools such as sandbox platforms, Sysmon, Wireshark, and process monitors. Behavioral data confirms and refines what static clues suggested.

A Practical Workflow

  • Safely acquire and hash the sample; store it in a controlled workspace.
  • Perform static analysis to form initial hypotheses about behavior and targets.
  • Build lightweight YARA rules to flag indicators early.
  • Run the sample in a sandbox, capture logs, network activity, and dropped files.
  • Correlate findings with threat intelligence and known IoCs.
  • Document steps and reproduce results for incident response and future hunts.

This approach helps teams prioritize alerts, understand treasury assets at risk, and share lessons with partners. Remember to work methodically and separate lab findings from production systems.

Key Takeaways

  • Static analysis reveals structure and intent without execution, guiding safe exploration.
  • Behavioral analysis shows real actions in a controlled setting, confirming threats.
  • A combined workflow uses both perspectives for clearer indicators and better response.