Crypto Challenge 6 - Signature

Prompt

Cyber Command: We have identified a set of 1000 possible flags, not all of them are the correct flag. However, the files with the correct flag should be signed by one of the certificates created by the included certificate authority.

Answers

What is the organization name of the certificate authority? (10 pts)
Windoge Certificate Authority

What is a valid flag from this set of files? (65 pts)
SKY-JGDP-4930

Steps I Took

Q1 — Opened the provided ca.crt file. The organization name was listed directly in the certificate details.

Q2 — Googled how to bulk verify exe certificate signatures. Found a script using osslsigncode to check all 1000 files at once. It identified flag_746.exe as having a valid signature. Opened the exe with Wine and it returned the flag.