$ 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

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Challenge CTF Weight Has
Storytime_The_Shocking_Conclusion
#xor-decoding#static-reversing
 BCACTF 2021 – files wu 2
Sanity
#xor-cipher
 IJCTF 2021 – files wu 2
LessEQualmore
#vm-reversing
 HITCON 2023 Quals 99.75 files wu 2
restless
#vm-reversing
 hxp 2020 94.00 files wu 2
Ware
#upx-unpacking#reverse-engineering
 0x41414141 2021 – files wu 2
hash
#upx-unpacking#golang-reversing
 0x41414141 2021 – files wu 2
thats_a_lot_of_fish
#typescript-type-system#custom-vm
 PlaidCTF 2020 93.15 files wu 2
cup-of-tea
#tea-cipher#reversing#ida
 Defcamp 2022 – files wu 2
SanityCheck
#strings-extraction
 UACTF 2022 – files wu 2
CatsAtPlay
#strings
 RITSEC 2023 – files wu 2
polymer
#strings
 PBjar 2021 23.18 files wu 2
Super_Super_Mario
#static-binary-patching
 ICHSA 2021 – files wu 2
no_strings
#static-analysis
 DownUnderCTF 2021 – files wu 2
Fleshwound
#scratch#visual-programming
 RITSEC 2021 – files wu 2
Ducky1
#rubber-ducky-decode
 BYUCTF 2023 – files wu 2
Cereal_Killer_02
#reversing#xor-rotating-key#known-plaintext
 DEADFACE 2023 – files wu 2
Failed_Logins
#reversing#string-decoding#base64
 DeconstruCT.F 2021 19.69 files wu 2
RevMePlx
#reversing#string-analysis#name-divecount-check
 CyberSecurityRumble 2022 62.00 files wu 2
T_the_weakest
#reversing#side-channel
 TSG 2023 – files wu 2
optimized
#reversing#self-modifying-code
 TSG 2021 – files wu 2
geoguesser
#reversing#prng#janet
 UIUCTF 2023 – files wu 2
parallelism
#reversing#permutation-recovery#gdb#memcmp
 DiceCTF 2023 36.70 files wu 2
MineGame
#reversing#minesweeper#prng-prediction
 DaVinciCTF 2022 24.50 files wu 2
digital_play
#reversing#logic-circuit
 Tamil 2021 14.13 files wu 2
Cereal_Killer_01
#reversing#ghidra#stack-string-decode#debugger-patch
 DEADFACE 2023 – files wu 2
Cereal_Killer_05
#reversing#gdb#memory-search
 DEADFACE 2023 – files wu 2
Tiny_interpreter
#reversing#custom-interpreter#bytecode
 DCTF 2021 – files wu 2
HomeworkHelp
#reversing#buffer-overflow#xor
 WolvCTF 2023 24.33 files wu 2
finals-simulator
#reverse-input-validation
 LA 2023 – files wu 2
Doki_Doki_Anticheat
#renpy
 Hack.lu 2023 94.73 files wu 2
GuessThePassword
#python-reversing#custom-encoding
 RITSEC 2023 – files wu 2
scrambler
#python-bytecode
 HSCTF 2021 – files wu 2
decompile-me
#pyc-decompilation
 SEETF 2023 – files wu 2
obscure
#pyc-decompilation
 Tamil 2021 14.13 files wu 2
Do_you_even_lift_bro
#prng
 Hack.lu 2024 100.00 files wu 2
weenie_hut_general
#predictable-prng#fixed-srand-seed
 b01lers 2021 22.99 files wu 2
unionware
#powershell-deobfuscation#ransomware
 Union 2021 24.34 files wu 2
1337RFCs
#polyglot-file
 Intent 2021 19.97 files wu 2
Mini_Pokemon
#pokemon-mini#emulator-debugging#s1c88
 PlaidCTF 2021 99.64 files wu 2
babyrev
#password-check-reversing
 NahamCon 2022 24.61 files wu 2