crwnctl

Writeups

CTF Solutions & Case Studies

Technical walkthroughs of cybersecurity challenges, featuring reconnaissance, exploitation techniques, reasoning, and lessons learned.

Currently Featured

picoCTF 2026 Writeups

A curated collection of detailed writeups from picoCTF 2026, with additional challenges being added over time.

Open Repository →

May 2026

Binary Digits

A .bin file containing only ones and zeros hides a flag image. Solved by piping the binary data through CyberChef's From Binary → Render Image recipe.

picoCTFForensicsCyberChefBinary
Read

May 2026

Password Profiler

Used CUPP to generate a targeted wordlist from provided user info, then ran it against a SHA-1 hash checker script to crack the password and retrieve the flag.

picoCTFGeneral SkillsCUPPPassword Cracking
Read

Apr 2026

Shared Secrets

Asymmetric encryption challenge with the private key provided. Adapted the encryption script to decrypt by swapping inputs and substituting real keys.

picoCTFCryptographyPythonAsymmetric
Read

Apr 2026

StegoRSA

RSA private key hidden in JPEG metadata as a hex comment. Extracted with ExifTool, decoded in CyberChef, then used OpenSSL to decrypt the flag file.

picoCTFCryptographyRSASteganographyExifTool
Read

Apr 2026

Quizploit

Quiz-style binary analysis covering ELF inspection, checksec protections, stack overflow identification, and locating the win() function address via objdump.

picoCTFBinary ExploitationchecksecobjdumpELF
Read

Apr 2026

Sudo Make Me A Sandwich

SSH access with sudo rights to run emacs as root. Escalated privileges by spawning a shell through emacs eval to read the flag.

picoCTFGeneral SkillsPrivilege Escalationsudoemacs
Read

Apr 2026

Piece by Piece

Reconstructed a split zip archive from file fragments using cat, then extracted with the provided password to reveal the flag.

picoCTFGeneral SkillsLinuxFile SplittingZip
Read

Apr 2026

Bytemancy-0

Prompt asks for ASCII decimal 101 repeated side-by-side. Walkthrough covers why the check maps to 'eee' and how to solve quickly from source inspection.

picoCTFGeneral SkillsASCII
Read

Apr 2026

Bytemancy-1

Byte-conjuring variant where user input must match \x65 repeated 1751 times. Covers translating the condition into the exact required payload.

picoCTFGeneral SkillsScripting
Read

Apr 2026

Printer Shares

SMB share enumeration using smbclient to locate exposed printer-share artifacts and recover the challenge file from a misconfigured network share.

picoCTFNetworkingSMBEnumeration
Read

Apr 2026

My Git

Git-focused challenge: inspect repository contents, follow README instructions, and use basic Git/file operations to recover the flag.

picoCTFGeneral SkillsGit
Read