Description
Software packing is a method of compressing or encrypting an executable. Packing an executable changes the file signature in an attempt to avoid signature-based detection. Most decompression techniques decompress the executable code in memory. Utilities used to perform software packing are called packers. Example packers are MPRESS and UPX. A more comprehensive list of known packers is available, (Citation: Wikipedia Exe Compression) but adversaries may create their own packing techniques that do not leave the same artifacts as well-known packers to evade defenses. Adversaries may use virtual machine software protection as a form of software packing to protect their code. Virtual machine software protection translates an executable's original code into a special format that only a special virtual machine can run. A virtual machine is then called to run this code.(Citation: ESET FinFisher Jan 2018)
Threat-Mapped Scoring
ATT&CK Kill Chain Metadata
- Tactics: defense-evasion
- Platforms: Windows, macOS
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Detection Guidance:
Use file scanning to look for known software packers or artifacts of packing techniques. Packing is not a definitive indicator of malicious activity, because legitimate software may use packing techniques to reduce binary size or to protect proprietary code.