Adversaries may attempt to make a payload difficult to analyze by removing symbols, strings, and other human readable information. Scripts and executables may contain variables names and other strings that help developers document code functionality. Symbols are often created by an operating system’s `linker` when executable payloads are compiled. Reverse engineers use these symbols and strings to analyze code and to identify functionality in payloads.(Citation: Mandiant golang stripped binaries explanation)(Citation: intezer stripped binaries elf files 2018) Adversaries may use stripped payloads in order to make malware analysis more difficult. For example, compilers and other tools may provide features to remove or obfuscate strings and symbols. Adversaries have also used stripped payload formats, such as run-only AppleScripts, a compiled and stripped version of AppleScript, to evade detection and analysis. The lack of human-readable information may directly hinder detection and analysis of payloads.(Citation: SentinelLabs reversing run-only applescripts 2021)
Creation of run-only AppleScripts or Mach-O binaries lacking symbol table and string references, especially when dropped by user space scripting engines or staging apps.
Executable or binary files created without symbol tables or with stripped sections, especially by non-user shell processes or compilers invoked outside standard dev paths.
Inbound binary payloads transferred over HTTP/S with compressed or encoded headers, lacking signature markers or metadata indicative of compiler/toolchain.