𝑻𝒓𝒖𝒆𝑷𝒐𝒍𝒚𝒈𝒍𝒐𝒕

Truepolyglot is polyglot file generator project. It means the generated file is composed of several file formats. The same file can be opened as a ZIP file and as a PDF file for example. The idea of this project comes from the work of Ange Albertini, International Journal of Proof-of-Concept or Get The Fuck Out and Julia Wolf that explain how we can build a polyglot file.

Polyglot file can be boring to build, even more if you want to respect the file format correctly.

That’s why I decided to build a tool to generate them.

My main motivation was the technical challenge.

Features and versions

Description Version Build a polyglot file valid as PDF and ZIP format and that can be opened with 7Zip and Windows Explorer POC Add a stream object in the PDF part POC Polyglot file checked without warning with pdftocairo >= 1.0 Polyglot file checked without warning with caradoc >= 1.0 Rebuild the PDF Xref Table >= 1.0 Stream object with the correct length header value >= 1.0 Add the format “zippdf”, file without offset after the Zip data >= 1.1 Polyglot file keeps the original PDF version >= 1.1.1 Add the “szippdf” format without offset before and after the Zip data >= 1.2 Fix /Length stream object value and the PDF offset for the szippdf format >= 1.2.1 PDF object numbers reorder after insertion >= 1.3 Add the format “pdfany” a valid PDF with custom payload content in the first and the last objet >= 1.5.2 Add “acrobat-compatibility” option to allow szippdf to be read with Acrobat Reader (thanks Ange Albertini) >= 1.5.3 Add the format “zipany” a valid ZIP with custom payload content at the start and between LHF and CD >= 1.6

Polyglot file compatibility

Software Formats status Acrobat Reader pdfzip, zippdf, szippdf, pdfany OK Sumatra PDF pdfzip, zippdf, szippdf, pdfany OK Foxit PDF Reader pdfzip, zippdf, szippdf, pdfany OK Edge pdfzip, zippdf, szippdf, pdfany OK Firefox pdfzip, zippdf, szippdf, pdfany OK 7zip pdfzip, zippdf, zipany OK with warning 7zip szippdf OK Explorer Windows pdfzip, zippdf, szippdf, pdfany, zipany OK Info-ZIP (unzip) pdfzip, zippdf, szippdf, pdfany, zipany OK Evince pdfzip, zippdf, szippdf, pdfany OK pdftocairo -pdf pdfzip, zippdf, szippdf, pdfany OK caradoc stats pdfzip, pdfany OK java -jar szippdf OK

Examples

Usage

usage: truepolyglot format [options] output-file Generate a polyglot file. Formats availables: * pdfzip: Generate a file valid as PDF and ZIP. The format is closest to PDF. * zippdf: Generate a file valid as ZIP and PDF. The format is closest to ZIP. * szippdf: Generate a file valid as ZIP and PDF. The format is strictly a ZIP. Archive is modified. * pdfany: Generate a valid PDF file with payload1 file content as the first object or/and payload2 file content as the last object. * zipany: Generate a valid ZIP file with payload1 file content at the start of the file or/and payload2 file content between LFH and CD. positional arguments: {pdfzip,zippdf,szippdf,pdfany,zipany} Output polyglot format output_file Output polyglot file path optional arguments: -h, --help show this help message and exit --pdffile PDFFILE PDF input file --zipfile ZIPFILE ZIP input file --payload1file PAYLOAD1FILE Payload 1 input file --payload2file PAYLOAD2FILE Payload 2 input file --acrobat-compatibility Add a byte at the start for Acrobat Reader compatibility with the szippdf format --verbose {none,error,info,debug} Verbosity level (default: info) TruePolyglot v1.6.2

Code

git clone https://git.hackade.org/truepolyglot.git/

or download truepolyglot-1.6.2.tar.gz

How to detect a polyglot file ?

You can use binwalk on a file to see if composed of multiple files.

truepolyglot@hackade.org

Credits

Copyright © 2018-2019 ben@hackade.org

TruePolyglot is released under Unlicence except for the following libraries: