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Technical knowledge library
Technical walkthroughs documenting how I approach authorized CTF challenges, investigate evidence, test assumptions, use security tooling, and turn the final solution into a reproducible explanation.
7 documented walkthroughs
A practical introduction to encodings, XOR, byte operations, and the foundational techniques used throughout CryptoHack.
Solving a Vigenère cipher challenge by identifying the cipher structure and applying the supplied key correctly.
A byte-at-a-time ECB oracle attack demonstrating how deterministic block encryption can disclose an appended secret.
Recovering an AES key by exploiting CBC key-and-IV reuse together with plaintext disclosed through an error response.
Investigating reused one-time-pad keystreams with XOR relationships, crib dragging, and partial plaintext recovery.
Breaking weak RSA by factoring the public modulus, rebuilding the private key, and decrypting the supplied ciphertext.
Tracing stream-cipher behavior and byte-level transformations to recover the challenge secret with a reproducible script.
3 documented walkthroughs
Following a multi-stage public-information trail through usernames, GitHub, PGP data, cryptocurrency activity, Wi-Fi clues, and travel evidence.
Correlating public profiles and platform clues while documenting how automated reconnaissance supports manual verification.
An OSINT investigation built around cached public activity, identity clues, and evidence gathered across multiple platforms.
4 documented walkthroughs
Extracting recursively embedded files from an image and validating each layer until the hidden evidence is recovered.
Repairing a malformed BMP header byte by byte, calculating the correct dimensions, and revealing concealed image data.
Investigating a packet capture with Wireshark to reconstruct suspicious traffic, extract indicators, and follow the compromise timeline.
Examining a disk image with Sleuth Kit utilities to locate partitions, enumerate files, and recover the target artifact.
3 documented walkthroughs
Enumerating a Linux host and abusing an overly permissive sudo rule to reach protected data through an authorized binary.
A broad Linux privilege-escalation lab covering enumeration, weak permissions, scheduled tasks, capabilities, NFS, and multiple paths to root.
A complete web-to-root path using service enumeration, directory discovery, upload-filter bypass, shell access, and Linux privilege escalation.
5 documented walkthroughs
Inspecting and modifying client-side cookie state to demonstrate why authorization decisions cannot be trusted to the browser.
Tracing a vulnerable authentication query and constructing a controlled SQL injection to bypass the login check.
Turning weak profile-image upload validation into server-side code execution and controlled file access.
Analyzing stored XSS, browser state, and a report workflow to understand how attacker-controlled content reaches a privileged session.
Recovering a weak JWT signing secret and forging an authorized token to access protected application functionality.
5 documented walkthroughs
A first stack-overflow exercise showing how oversized input reaches a crash handler and triggers the challenge win condition.
Calculating a stack offset, controlling EIP, and redirecting execution to an existing win function in a vulnerable binary.
Using a leaked runtime address and symbol offsets to calculate the randomized location of a target function in a PIE binary.
Finding the exact overflow offset and building a minimal ROP chain that redirects execution to the supplied win function.
Building a ROP chain from existing gadgets, a useful command string, and a PLT function to read the challenge flag.
3 documented walkthroughs
Using GDB to inspect program behavior, bypass an unnecessary delay, and reveal the flag-producing execution path.
Identifying a UPX-packed binary, unpacking it, and examining the recovered program to locate the embedded secret.
Combining Ghidra and GDB to trace a quiet binary as it reconstructs its flag through runtime string operations.