Entropy (Shannon)
Definition
Per-byte information density of a file or section. Plain code sits around 5.5; packed or encrypted sections exceed 7.0. A PE with a high-entropy section that is not a known packer signature is almost always packed; the entropy line is the first static signal of obfuscation.
Related terms
- ImpHash
- Mandiant's hash of the ordered list of imported functions in a PE file's import table. Survives recompilation that does not change imports;...
- IoC (Indicator of Compromise)
- Observable artefact linked to malicious activity. File hashes (MD5, SHA-256, ImpHash, ssdeep, TLSH), IPs, domains, URLs, registry keys, mutex names, named pipes,...
- PE (Portable Executable) Header
- The Windows executable file format. Starts with an MZ DOS stub, points to a PE signature, then a COFF file header, an...
- Volatility 3
- Open-source memory forensics framework, Python 3 rewrite of Volatility 2. Symbol-based (PDB symbols on Windows) instead of profile-based, supports modern Windows 10/11...
- YARA
- Pattern-matching language for malware classification. Rules combine string and byte-pattern conditions with metadata. Used by VirusTotal, every major sandbox, and most threat-intel...
Explained in
- Malware Forensics: Static, Dynamic, Sandbox and Memory AnalysisPer-byte information density of a file or section. Plain code sits around 5.5; packed or encrypted sections exceed 7.0. A PE with a high-entropy section that i...