Obfuscated Files or Information: Software Packing
Adversaries may perform software packing or virtual machine software protection to conceal their code. 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. 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.
Utilities used to perform software packing are called packers. Example packers are MPRESS and UPX. A more comprehensive list of known packers is available,  but adversaries may create their own packing techniques that do not leave the same artifacts as well-known packers to evade defenses.
Employ heuristic-based malware detection. Ensure updated virus definitions and create custom signatures for observed malware.
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.
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