MinGW-w64 Build Artifacts

Distinguishing features of binaries produced by the MinGW-w64 (Minimalist GNU for Windows) GCC toolchain.

Structural Indicators

• Linker version: Major=2, Minor=0x24 (36) or similar — ld from GNU Binutils, not MSVC link.exe. ^[pefile.txt:46]
• Runtime strings: __shmem3_winpthreads_tdm_, mingw-w64, winpthread error paths. ^[floss.txt:966]
• CRT imports: msvcrt.dll rather than ucrtbase.dll / vcruntime140.dll.
• Pseudo-relocation handler: __mingw_initltsdrot_lr / __mingw_initltsdyn_force present in startup code.
• No Rich header: MSVC binaries carry a Rich PE header; MinGW binaries do not.

Implications for Attribution

MinGW-w64 is common in cross-compilation environments (Linux → Windows), open-source ports, and malware builders that avoid MSVC licensing. Its presence alone is not malicious, but combined with stripped symbols, no overlay, and minimal imports it is a frequent fingerprint for custom droppers and loaders.

Pages Where Observed

• unclassified-mingw64-https-stager — stage-1 downloader with winpthreads runtime
• 9d2ca3 — Amadey-dropped MinGW-w64 encrypted .data payload cluster
• chacha8 — MinGW-w64 ChaCha20 destructive encryptor
• esmk-crypter-loader — MinGW-w64 reflective PE loader
• uniqfile — MinGW-w64 .rdata reflective loader (e79a525e)