| name | analyzing-elf-binaries-on-linux |
| description | Statically analyzes Linux ELF malware: ELF header and sections, dynamic symbols and imports, segment permissions, embedded strings, and packing indicators to infer capability without execution. Activates for requests to analyze an ELF binary, Linux malware, or shared object. |
| domain | cybersecurity |
| subdomain | malware-analysis |
| tags | ["malware","static-analysis","elf","linux","symbols","entropy"] |
| version | 1.0.0 |
| author | analyst-ai-pack |
| license | Apache-2.0 |
| mitre_attack | ["T1027","T1059.004","T1129"] |
| d3fend | ["D3-FA","D3-FCR"] |
| references | ["ELF specification (System V ABI) — https://refspecs.linuxfoundation.org/elf/elf.pdf","pyelftools — https://github.com/eliben/pyelftools"] |
Analyzing ELF Binaries on Linux
When to Use
- You have a Linux executable or shared object and need to assess it statically.
- You want to read the ELF header, segments, dynamic symbols, and strings to infer behavior.
- You are checking for static linking, stripped symbols, or packing.
Do not use symbol absence as proof of nothing — stripped or statically linked Go/Rust
binaries hide structure; switch to disassembly when static metadata is thin.
Prerequisites
readelf/nm/strings (binutils) or pyelftools (pip install pyelftools).- The sample in neutralized form inside the lab.
Safety & Handling
- Static only: parse the file; do not set it executable or run it.
Workflow
Step 1: Read the ELF header
python scripts/analyst.py analyze sample.elf
Note class (ELF32/64), endianness, type (EXEC/DYN/REL), machine (x86-64, ARM, MIPS), and
whether it is stripped.
Step 2: Examine segments and section permissions
Writable+executable segments, or a single large segment, suggest packing or self-modifying
code. Compare PT_LOAD permissions against expectations.
Step 3: Inspect dynamic symbols and needed libraries
Imported functions hint at capability: socket/connect (network), ptrace (anti-debug or
injection), fork/execve (process control), crypt/EVP_* (encryption).
Step 4: Detect static linking and packing
Static binaries lack a dynamic symbol table and NEEDED entries. High whole-file entropy and
a tiny section table suggest a packer (e.g. UPX leaves UPX! markers).
Step 5: Skim strings and constructors
Check .init_array/constructors (code before main), and strings for paths, URLs, and shell
commands.
Validation
- Header
type and segment permissions are consistent with the inferred behavior.
- Imported symbols correspond to plausible capabilities.
- Packing call (entropy + missing sections) matches the strings observed.
Pitfalls
- Assuming dynamic symbols are complete — they only cover imported/exported names, not
internal functions.
- Treating a stripped Go binary as "empty"; its structure lives in runtime metadata, not the
symbol table.
- Ignoring constructors/
.init_array, which run before main.
References
