DFRWS 2017 Europe - Proceedings of the Fourth Annual DFRWS EuropeForce Open: Lightweight black box file repair

We present a novel approach for automatic repair of corrupted files that applies to any common file format and does not require knowledge of its structure. Our lightweight approach modifies the execution of a file viewer instead of the file data and makes use of instrumentation and execution hijacking, two techniques from software testing. It uses a file viewer as a black box and does not require access to its source code or any knowledge about its inner workings. We present our implementation of this approach and evaluate it on corrupted PNG, JPEG, and PDF files.