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.(Citation: ESET FinFisher Jan 2018)
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.(Citation: Awesome Executable Packing)
View in MITRE ATT&CK®| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name |
|---|---|---|---|---|
| SI-02 | Flaw Remediation | Protects | T1027.002 | Software Packing |
| SI-03 | Malicious Code Protection | Protects | T1027.002 | Software Packing |
| SI-04 | System Monitoring | Protects | T1027.002 | Software Packing |
| SI-07 | Software, Firmware, and Information Integrity | Protects | T1027.002 | Software Packing |