Writeup in progress
Currently making the solution for Powershelly and the walkthrough will be published here as soon as it's ready.
Check back soon - or follow our latest updates on the homepage- to be notified when the full writeup goes live.
Powershelly
Published: April 2, 2026
Want more picoCTF 2021 writeups?
Useful tools for Reverse Engineering
- Number Base ConverterConvert numbers between binary, octal, decimal, and hexadecimal instantly. Enter any value and see all four bases update in real time.
- Bit Shift CalculatorPerform left/right bit shifts and see the result across binary, octal, decimal, and hex.
- Binary to Hex ConverterNormalize binary strings and convert them instantly to hexadecimal, decimal, and octal.
- Binary CalculatorPerform binary arithmetic (add, subtract, multiply, divide) with copyable outputs in every base.
More Reverse Engineering
- Reverse EngineeringEasy
Transformation
Unicode characters each encode two ASCII bytes packed via (ord(a)<<8)+ord(b). Extract both bytes to recover the flag.
- Reverse EngineeringMedium
ARMssembly 0
Read and trace ARM32 assembly to determine the return value: the function computes max(arg1, arg2) = 3742084308 = 0xdf0bacd4 in hex.
- Reverse EngineeringMedium
ARMssembly 1
Trace ARM32 shift and division: compute 68 << 2 = 272, then 272 / 3 = 90, which equals 0x0000005a in hexadecimal.