Prompt
Our analysts managed to get hold of a document that we believe has a flag on it. Can you recover it?
Walkthrough
This challenge asks you to download a file and recover a flag. This file looks like a PDF with lots of redacted portions.
Guide
To find the name of the program that exported this PDF file, try accessing a metadata viewer to find more information. Look at the “creator_tool” field. The same output can be used to find the PDF version that was used to make this file (look at the “pdf_version” field).
To find what software was used to redact this file and add a watermark, try using the PDF editor to removing the black box that is blocking the watermark. The box can be deleted by right clicking on the shape.
Doing the same for the box next to tlsSocket.getFlag() will reveal the flag. Alternatively, you can highlight the entire area around the box and the text behind the box can be copied to your clipboard.
Useful resources for this challenge:
- Metadata2go: https://www.metadata2go.com/view-metadata
Questions
1. What is the name of the program that exported this PDF file?
2. What PDF version is this file?
3. What software was used to redact the file and insert a watermark?
4. What is the flag?
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