Fortran ZIP Bomb — Live Demo (Educational)
This page hosts a working ZIP bomb generated by my open-source educational project fortran-zip-bomb, which demonstrates Fortran/C/C++ interop by building a real ZIP-format decompression bomb from scratch (genuine DEFLATE compression via zlib, correct CRC32 — it will actually decompress).
Read the companion blog post first if you haven’t — it explains what a ZIP bomb is and why this one behaves the way it does.
What happens if you extract it
- Compressed download: ~21 MB
- Decompressed size: ~10 GB across 1000 files
- Extracting it will consume ~10GB of disk space and noticeable CPU/memory while your unzip tool works through it.
Only do this in a disposable environment — a VM, a container, or a machine you don’t mind filling up temporarily. Do not extract this on a machine with limited free disk space. Do not extract it on shared/production infrastructure.
Download
Safe ways to test it
# Inspect the archive without extracting anything (always safe)
unzip -l fortran-zipbomb-demo.zip
# Verify integrity of a single entry without writing 10GB to disk
unzip -p fortran-zipbomb-demo.zip bomb_data_0.txt | wc -c
# Full extraction (only in a VM/container with >10GB free disk)
mkdir extract_test && cd extract_test
unzip ../fortran-zipbomb-demo.zip
Source code, build instructions, and technical write-up of how the DEFLATE-based amplification works are in the GitHub repository.