$ 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
Its_Not_Pwn_I_Swear
#overridden-stack-check
 ImaginaryCTF 2021 – files wu 1
two_shortest
#oob-index#free-pascal#got-overwrite
 RCTF 2021 – files wu 1
padlock
#obfuscated-c#quine-reversing
 b01lers 2023 36.84 files wu 1
Thief
#nuitka-binary-reversing
 MetaRed 2021 – files wu 1
LittleBabyRev
#nim#reversing
 Securinets 2021 Quals 41.71 files wu 1
Easy_NFT
#nftables
 Dragon 2021 99.33 files wu 1
NSTFTP
#network-protocol-reversing#pcap-analysis#custom-ftp#backdoor
 DawgCTF 2021 23.29 files wu 1
ElectroNES
#nes-reversing#6502
 BlueHens 2023 24.61 files wu 1
wreckme_again
#negabinary-fft
 hxp 2024 – files wu 1
Buried_Treasure
#multi-stage-unpacking#memfd-create#xor#strace-dump
 RITSEC 2026 – files wu 1
dotsbedashing
#morse-code#xor#bit-rotation
 VuwCTF 2026 25.00 files wu 1
Apps
#mit-app-inventor#aia-reversing
 Bucket 2023 24.80 files wu 1
A_Fun_Game
#memory-editing#cheat-engine#dotnet-mono
 BCACTF 2021 – files wu 1
Tridea
#meet-in-the-middle (mitm)#block-cipher#anti-debugging
 VolgaCTF 2024 Quals 35.91 files wu 1
yasashiimon
#mds-sbox-inversion
 hxp 2024 – files wu 1
Miz
#maze-solving
 InCTF 2021 70.41 files wu 1
McFlagChecker
#matrix-inversion-reversing
 LA 2025 – files wu 1
Mayhem
#malware-unpacking
 NahamCon 2023 34.82 files wu 1
susware
#malware-analysis#unpacking
 SEETF 2022 – files wu 1
malwy
#malware-analysis#reversing#ida
 Defcamp 2022 – files wu 1
Fruit_Deals
#maldoc#vba-macro#obfuscation
 UTCTF 2024 – files wu 1
RetroZeit
#m68k
 Dragon 2020 98.00 files wu 1
Lunar_Unraveling_Adventure
#lua-5.1-bytecode-decompilation#unluac
 1337UP 2023 24.23 files wu 1
LoongArch
#loongarch#instruction-set-reversing
 RCTF 2021 – files wu 1
confounded-pondering-unit
#logisim-cpu-reversing
 MapleCTF 2022 24.05 files wu 1
Digitally_Encrypted_2.99999
#logic-circuit-reversing#shift-xor-cipher-inversion
 BCACTF 2021 – files wu 1
Digitally_Encrypted_3
#logic-circuit-reversing#shift-add-xor-cipher
 BCACTF 2021 – files wu 1
Layers
#llvm-obfuscation#control-flow-flattening
 3kCTF 2021 24.14 files wu 1
nobranch7e4
#linear-algebra
 hxp 2020 94.00 files wu 1
EbookDRM
#ld-preload#binary-patching#library-hooking
 UTCTF 2022 – files wu 1
Revvy_Chevy
#lcg-keystream
 MetaCTF 2021 – files wu 1
Sheepish
#lambda-calculus
 ImaginaryCTF 2023 34.52 files src wu 1
Back_to_the_Lab_3
#labview-reversing#bit-rotation#binary-patching
 DawgCTF 2021 23.29 files wu 1
CyberDark_0x02Installer
#keygen#license-key-reversing
 darkCON 2021 24.06 files wu 1
faulty_road
#kernel#reversing
 TRX 2026 – files wu 1
highest_power
#jit-vm#arm-reversing#bruteforce
 Pwn2Win 2021 83.41 files wu 1
turbocrab
#jit-shellcode#substitution-recovery
 corCTF 2022 24.92 files src wu 1
JS_is_Awesome
#javascript-deobfuscation#xor
 VULNCON 2021 – files wu 1
Obfuscated
#java-reversing#string-obfuscation#per-chunk-check
 DaVinciCTF 2022 24.50 files wu 1
Cereal_Killer_04
#java-reversing#jar-decompilation#procyon
 DEADFACE 2023 – files wu 1