$ ctf42

Reverse CTF challenges

4,044 Reverse CTF challenges from 397 CTFs (2011–2026), 511 with writeups.

Top reverse techniques

#reversing 77 #xor 24 #z3 15 #vm-reversing 13 #constraint-solving 10 #static-analysis 9 #strings 9 #android 9 #anti-debugging 7 #symbolic-execution 6 #dotnet-reversing 6 #xor-cipher 5 #angr 5 #windows-reversing 5 #binary-patching 5

Challenges

Filter and sort these in the challenge browser →

Challenge CTF Weight Has
nimrev
#nim-reversing#bitwise-not
 CakeCTF 2022 – files wu 2
Dotty
#morse-code#strings
 RaRCTF 2021 24.53 files wu 2
ransomwaRE
#malware-reversing#date-seeded-key#aes-ctr#keystream-reuse
 CSAW 2021 Quals 20.54 files wu 2
Digitally_Encrypted_1
#logic-circuit-reversing#xor-cipher
 BCACTF 2021 – files wu 2
Digitally_Encrypted_2
#logic-circuit-reversing#xnor-cipher
 BCACTF 2021 – files wu 2
Entropy
#lcg#z3-solver
 BlueHens 2021 22.62 files wu 2
tex_based_adventure
#latex
 hxp 2022 – files wu 2
pwnykey
#keygen#reversing
 UIUCTF 2023 – files wu 2
caterpillar
#js-deobfuscation
 LA 2023 – files wu 2
required
#javascript-reversing
 hxp 2022 – files wu 2
Starbucks
#java-reversing#decompilation
 UMDCTF 2021 – files wu 2
MatrixLab1
#java-bytecode#reversing
 SekaiCTF 2022 24.86 files wu 2
grub
#grub-cfg#regex-constraints#z3
 OMH 2021 – files wu 2
baby_rev
#ghidra-static-analysis
 BITSCTF 2024 – files wu 2
switcheroo
#gdb-bruteforce
 LA 2023 – files wu 2
Wait_this_isnt_C
#fortran-reversing
 BCACTF 2021 – files wu 2
I_Hate_Python
#fixed-seed-prng
 MetaCTF 2021 – files wu 2
MisleadingSteps
#false-flag#dynamic-analysis
 VishwaCTF 2021 – files wu 2
Blue_Hens
#esoteric-language#vm-reversing
 BlueHens 2023 24.61 files wu 2
mystery-methods
#encoding-chain
 HSCTF 2023 – files wu 2
flagsaver
#dotnet-reversing#image-unscramble
 OMH 2021 – files wu 2
AliceInCeptionland
#dotnet-reversing#dnspy
 corCTF 2021 24.92 files wu 2
bestsoftware
#dotnet-reversing
 SEETF 2022 – files wu 2
Game_Graphics_Debugging
#dll-hijacking#tls-callback#xor
 WolvCTF 2024 35.25 files wu 2
BabyRe
#crackme#anti-disassembly#ncurses
 Zh3r0 2021 – files src wu 2
zoom_zoom_vision
#cpp-reversing#substitution-cipher
 corCTF 2021 24.92 files wu 2
EXCELlent
#constraint-solving
 hxp 2020 94.00 files wu 2
mercy
#clemency
 HITCON 2021 – files wu 2
roulette_wheel
#c++-reversing#predictable-rng
 b01lers 2021 22.99 files wu 2
Baby-rev
#bruteforce-reversing
 LakeCTF 2022 Quals 23.96 files wu 2
Facile
#binwalk#strings
 VishwaCTF 2021 – files wu 2
Rotations
#binary-patching#caesar-cipher
 VishwaCTF 2021 – files wu 2
Automatic_Rejection_Machine
#arm-reversing
 m0leCon 2021 Quals 24.55 files wu 2
BasicRev
#angr#symbolic-execution
 BYUCTF 2022 – files src wu 2
Run_of_the_Mill
#angr
 Dragon 2021 99.33 files wu 2
ezpz
#android#firebase-firestore-leak
 darkCON 2021 24.06 files wu 2
Crack_Me
#android#firebase
 SekaiCTF 2024 36.96 files wu 2
Binary_shrink BraekerCTF 2024 24.72 files wu 2
Primitive_Reversing UMassCTF 2024 43.10 files wu 2
Anonymous 1337UP 2023 24.23 files wu 2