Packet Capture to Executable Analysis
Recovered a binary from network-capture data, analyzed its runtime behavior, and reconstructed a cryptographic transformation.
Publication context. This article summarizes an independently completed technical interview exercise using original commentary. The challenge was provided by a third party; the exercise is not represented as my own product, a public vulnerability, or a commissioned professional engagement. Original company branding, challenge assets, flags, and step-by-step solution details have been omitted.
The problem
The starting evidence was packet-capture data containing material associated with a Linux executable. After restoration, the program exited unexpectedly, and its encrypted output could not be understood from network traffic alone.
Research methodology
- Inspected captured conversations and reconstructed an executable artifact from the relevant raw bytes.
- Used GDB and Ghidra to investigate startup behavior, failure conditions, and the role of encrypted data.
- Examined socket-driven behavior in a controlled environment and used a small C implementation to validate the decryption workflow.
Tools & techniques
WiresharkHex editorGDBGhidraNcatC / OpenSSL
Result
The original assessment concluded with a successful decoding of the protected challenge output. The write-up does not establish a security defect in a real-world networked product.
What I practiced
Packet reconstruction, ELF analysis, debugging unexpected process termination, protocol reasoning, and cryptographic implementation testing.
A summary of a completed controlled assessment, not a disclosure of a third-party vulnerability. Results refer only to the exercise materials described.