$ 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
whatever_floats_your_boat
#vm-reversing#floating-point#mxcsr
 corCTF 2025 82.00 files wu 1
vmquack
#vm-reversing#custom-architecture
 corCTF 2021 24.92 files wu 1
highly-optimized
#vm-reversing#bytecode-interpreter
 UofTCTF 2025 23.90 files wu 1
fvm
#vm-reversing#bytecode#x87-fpu
 zer0pts 2023 52.62 files wu 1
bubble
#vm-reversing#bytecode
 corCTF 2025 82.00 files wu 1
vmquack_s_vectorized_vices
#vm-reversing#avx512
 corCTF 2023 36.97 files wu 1
vmquacks_revenge
#vm-reversing#anti-tampering
 corCTF 2022 24.92 files src wu 1
snake-jazz
#vm-reversing
 FE-CTF 2022 – files wu 1
compUDer
#vm-reversing
 BlueHens 2021 22.62 files wu 1
Obfuscation
#vm-obfuscation#bytecode-devirtualization#angr#symbolic-execution
 CSAW 2024 Quals 21.80 files wu 1
indie_vmm
#vm-escape
 hxp 2021 99.41 files wu 1
Valgrind
#vex-ir#valgrind#caesar-cipher
 RCTF 2021 – files wu 1
Abnormal
#verilog-reversing
 ImaginaryCTF 2021 – files wu 1
My_Daily_Macros
#vba-macro-analysis#xlsm#office-document
 DEADFACE 2023 – files wu 1
imPACKful
#upx-unpacking
 1337UP 2023 24.23 files wu 1
tour
#traveling-salesman#floyd-warshall#dynamic-programming
 PBjar 2021 23.18 files wu 1
nips
#tea-cipher#upx-unpacking#mips
 BCACTF 2025 – files wu 1
Star
#tar-wildcard-injection
 justCTF 2024 Quals 77.17 files wu 1
vm-v2
#systemverilog-vm-reversing
 MapleCTF 2022 24.05 files wu 1
DragonPit
#symbolic-execution#strcmp
 UMDCTF 2022 – files wu 1
Circuitry_magic
#symbolic-execution
 m0leCon 2022 Quals 36.00 files wu 1
Easy_RE_Challenge
#symbol-guided-static-analysis#xor-rol-inversion#decoy-path-elimination
 BDSec 2026 15.62 files wu 1
Welcome
#strings-analysis
 n00bzCTF 2023 15.12 files wu 1
Storytime_The_Opening_Gambit
#strings#static-analysis#plaintext-flag
 BCACTF 2021 – files wu 1
Just-Passw0rd
#strings
 WaniCTF 2023 24.99 files wu 1
ReadingList
#strings
 UTCTF 2023 – files wu 1
I_HATE_THIS_APP
#static-string-analysis
 LYKNCTF 2026 – files wu 1
Secure_Bank
#static-analysis#ltrace#hardcoded-credentials
 1337UP 2024 – files wu 1
back-to-basics
#static-analysis
 HSCTF 2023 – files wu 1
Saw
#static-analysis
 FwordCTF 2021 24.42 files wu 1
Lightningrod
#stateful-xor-cipher
 K3RN3LCTF 2021 24.37 files wu 1
meow_meow
#state-machine-reversing
 LA 2024 – files wu 1
Lost_Canary
#stack-buffer-overflow#canary-bypass
 UIUCTF 2024 – files wu 1
Back_to_the_past
#srand-time-seed#lcg#bruteforce
 PwnMe 2025 Quals 24.95 files wu 1
Symmetry_1
#spn-cipher-inversion
 KalmarCTF 2024 24.21 files wu 1
Control_Freak_2
#splitmix64-prng
 LYKNCTF 2026 – files wu 1
Credits
#spi-logic-analyzer
 MetaRed 2021 – files wu 1
FunFact
#single-byte-xor
 BYUCTF 2022 – files src wu 1
Now_this_will_run_on_my_486
#sigill-jit
 IrisCTF 2025 34.30 files wu 1
Secure_comparator
#side-channel#timing-attack
 TeamItaly 2023 24.88 files wu 1