$ 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
Fast_Calculator UIUCTF 2023 – files src wu 2
babyshark KnightCTF 2022 17.38 files wu 2
existing-tooling TAMUctf 2022 – files wu 2
redo3 TAMUctf 2022 – files wu 2
Crina ASIS 2021 Finals 89.22 files wu 2
Very_TriVial_ReVersing RaRCTF 2021 24.53 files wu 2
beanstalk ASIS 2021 Quals 89.22 files wu 2
easteregg UMassCTF 2021 23.56 files wu 2
godness_dance SCTF 2021 – files wu 2
B1ll_Gat35 picoCTF 2019 – files wu 2
NeedForSpeed picoCTF 2019 – files wu 2
Magical_Mystery_Club
#z3-solver#constraint-solving
 COMPFEST 2021 – files wu 1
find_plut0
#z3-solver
 InCTF 2021 70.41 files wu 1
CEOs_Lost_Password
#z3#constraint-solving#java-reversing
 UofTCTF 2024 23.90 files wu 1
WednesdayThursdayFriday
#z3#constraint-solving
 VishwaCTF 2023 22.69 files wu 1
Omen
#z3
 FwordCTF 2021 24.42 files wu 1
flag_checker
#z3
 DownUnderCTF 2021 – files wu 1
T_reasure_Chest
#xtea
 RITSEC 2026 – files wu 1
EZrev
#xor-swap-reversal
 n00bzCTF 2023 15.12 files wu 1
Getting_Darryl_Back
#xor-decryption-reversing
 MetaCTF 2021 – files wu 1
RevEng
#xor-decryption#ghidra
 BYUCTF 2023 – files wu 1
XOR
#xor-decryption
 BCACTF 2024 – files wu 1
Crispy_Kelp
#xor-cipher
 IrisCTF 2025 34.30 files wu 1
unoriginal
#xor-cipher
 ImaginaryCTF 2024 49.81 files wu 1
x0rr3al
#xor#string-obfuscation
 vsCTF 2023 23.32 files wu 1
child-re
#xor#static-analysis
 WolvCTF 2023 24.33 files wu 1
ilikewords
#xor#kaprekar-constant
 VuwCTF 2026 25.00 files wu 1
Clockwork
#xor
 EnigmaXplore 2025 – files wu 1
brain-hurt
#xor
 HSCTF 2023 – files wu 1
ezrev
#xor
 Hayyim 2022 25.00 files wu 1
vault-door-6
#xor
 picoCTF 2019 – files wu 1
asm4
#x86-assembly#inline-asm-compile
 picoCTF 2019 – files wu 1
asm3
#x86-assembly#emulation
 picoCTF 2019 – files wu 1
asm1
#x86-assembly
 picoCTF 2019 – files wu 1
asm2
#x86-assembly
 picoCTF 2019 – files wu 1
Paired
#windows-reversing#ipc-postmessage#inter-process-code-injection#xor
 CyBRICS 2021 33.32 files wu 1
service
#windows-reversing#cryptoapi#aes
 zer0pts 2022 35.97 files wu 1
EtherealCrackme
#windows-reversing#anti-analysis
 VishwaCTF 2023 22.69 files wu 1
Ducks_Ping_Pong
#windows-driver-reversing#ioctl#veh
 V1T 2026 22.14 files wu 1
Revisual
#webgl-reversing
 HITCON 2024 Quals 100.00 files wu 1