2016weight 0.00ABCTF 2016

ABCTF 2016

38 challenges with 73 published community solutions between them. Solution links go to CTFtime’s task page, which aggregates every writeup for a challenge - individual blog posts rot, the aggregator does not.

Full task list on CTFtime

Misc11

Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.

Solve it with:Brainfuck and esolang decoder Cipher identifier and automatic decoder Regex tester with match offsets and capture groups Learn: Recognising encodings

Obfuscated 1 (Programming)
130 pts3 writeups
- programming
Same technique in picoCTF: Permissions, Specialer, Codebook
TGIF (Programming)
30 pts3 writeups
- programming
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 3 (Virtual Series)
35 pts2 writeups
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 1 (Virtual Series)
10 pts2 writeups
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 2 (Virtual Series)
15 pts2 writeups
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 4 (Virtual Series)
60 pts2 writeups
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 5 (Virtual Series)
75 pts2 writeups
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook
QSet3 (Programming)
200 pts1 writeup
- programming
Same technique in picoCTF: Permissions, Specialer, Codebook
RacecaR (Programming)
100 pts1 writeup
- programming
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 6 (Virtual Series)
75 pts1 writeup
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook
Virtual Box 7 (Virtual Series)
100 pts1 writeup
- virtualization
Same technique in picoCTF: Permissions, Specialer, Codebook

Web9

Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.

Solve it with:JWT decoder and signature verifier JWT alg=none bypass generator Web attack payload catalog JWT secret brute force Learn: Web attacks and session tokens

Chocolate (Web Exploitation)
50 pts3 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
The Flash (Web Exploitation)
35 pts3 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
AudioEdit (Web Exploitation)
200 pts2 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Elemental (Web Exploitation)
10 pts2 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Inj3ction (Web Exploitation)
170 pts2 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
L33t H4xx0r (Web Exploitation)
70 pts2 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Reunion (Web Exploitation)
150 pts2 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Get 'Em All (Web Exploitation)
80 pts1 writeup
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Impenetrable Fortress (Web Exploitation)
200 pts1 writeup
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3

Cryptography7

Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.

Solve it with:Cipher identifier and automatic decoder Vigenere cipher solver with automatic key recovery RSA decryption and attack runner Wiener’s attack on small RSA private exponents In-browser hash cracker with rule transforms Learn: Classical ciphers and frequency analysis Learn: RSA and the parameters that break it

A Small Broadcast (Cryptography)
125 pts3 writeups
- cryptography
Same technique in picoCTF: StegoRSA, Timestamped Secrets, AES-ABC
Encryption Service (Cryptography)
140 pts3 writeups
- cryptography
Same technique in picoCTF: StegoRSA, Timestamped Secrets, AES-ABC
Sexy RSA (Cryptography)
160 pts3 writeups
- cryptography
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle
Caesar Salad (Cryptography)
10 pts2 writeups
- cryptography
Same technique in picoCTF: Mod 26, New Caesar, credstuff
Custom Authentication (Cryptography)
160 pts2 writeups
- cryptography
Same technique in picoCTF: StegoRSA, Timestamped Secrets, AES-ABC
Old RSA (Cryptography)
70 pts1 writeup
- cryptography
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle
Yummi (Cryptography)
60 pts1 writeup
- cryptography
Same technique in picoCTF: StegoRSA, Timestamped Secrets, AES-ABC

Forensics6

Recover something from a file, a capture, or a disk image - often from a part of it the format says is unused.

Solve it with:File type identifier by magic bytes Magic byte and file signature table PCAP analyzer for CTF network forensics EXIF metadata viewer Learn: File forensics and carving Learn: Network forensics

GZ (Forensics)
30 pts3 writeups
- forensics
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions
Just open it (Forensics)
15 pts3 writeups
- forensics
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions
MoonWalk (Forensics)
60 pts2 writeups
- forensics
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions
Best Ganondorf (Forensics)
50 pts1 writeup
- forensics
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions
PasswordPDF (Forensics)
80 pts1 writeup
- forensics
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions
Zippy (Forensics)
120 pts1 writeup
- forensics
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions

Reverse engineering3

Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.

Solve it with:Strings extractor for binaries and blobs WebAssembly disassembler Java .class disassembler Python .pyc bytecode disassembler Learn: Binary exploitation

Frozen Recursion (Reverse Engineering)
250 pts2 writeups
- reversing
Same technique in picoCTF: WinAntiDbg0x100, WinAntiDbg0x200, WinAntiDbg0x300
Java Madness (Reverse Engineering)
50 pts1 writeup
- engineering
- reverse
Same technique in picoCTF: vault-door-1, vault-door-3, vault-door-4
JS Pls (Reverse Engineering)
80 pts1 writeup
- reversing
Same technique in picoCTF: WinAntiDbg0x100, WinAntiDbg0x200, WinAntiDbg0x300

OSINT2

Answer a question about the real world from public sources. The work is pivoting between identifiers, not exploiting anything.

Solve it with:EXIF metadata viewer QR code decoder

Drive Home (Reconaissance)
50 pts3 writeups
- recon
Same technique in picoCTF: Permissions, Specialer, Codebook
Archive Me (Reconaissance)
50 pts2 writeups
- recon
Same technique in picoCTF: Permissions, Specialer, Codebook

Misc11

Obfuscated 1 (Programming)

TGIF (Programming)

Virtual Box 3 (Virtual Series)

Virtual Box 1 (Virtual Series)

Virtual Box 2 (Virtual Series)

Virtual Box 4 (Virtual Series)

Virtual Box 5 (Virtual Series)

QSet3 (Programming)

RacecaR (Programming)

Virtual Box 6 (Virtual Series)

Virtual Box 7 (Virtual Series)

Web9

Chocolate (Web Exploitation)

The Flash (Web Exploitation)

AudioEdit (Web Exploitation)

Elemental (Web Exploitation)

Inj3ction (Web Exploitation)

L33t H4xx0r (Web Exploitation)

Reunion (Web Exploitation)

Get 'Em All (Web Exploitation)

Impenetrable Fortress (Web Exploitation)

Cryptography7

A Small Broadcast (Cryptography)

Encryption Service (Cryptography)

Sexy RSA (Cryptography)

Caesar Salad (Cryptography)

Custom Authentication (Cryptography)

Old RSA (Cryptography)

Yummi (Cryptography)

Forensics6

GZ (Forensics)

Just open it (Forensics)

MoonWalk (Forensics)

Best Ganondorf (Forensics)

PasswordPDF (Forensics)

Zippy (Forensics)

Reverse engineering3

Frozen Recursion (Reverse Engineering)

Java Madness (Reverse Engineering)

JS Pls (Reverse Engineering)

OSINT2

Drive Home (Reconaissance)

Archive Me (Reconaissance)

Other 2016 events