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unpackme
Published: July 20, 2023
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Useful tools for Reverse Engineering
- Hex ViewerView text or raw hex bytes as a xxd-style hex dump with byte offset, hex columns, and ASCII sidebar. Highlights printable characters and null bytes.
- 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.
Related reading
- Using GDB for CTF Reverse EngineeringA practical guide to GDB for CTF competitions: running binaries, setting breakpoints, reading registers, inspecting memory, and tracing through the Bit-O-Asm and GDB baby step challenge series.
- How to Use Ghidra for Reverse Engineering CTF ChallengesA practical guide to using Ghidra for CTF reverse engineering challenges -- importing binaries, reading decompiled C, finding flags in strings, and tracing logic with the Symbol Tree.
- How to Read and Analyze Hex DumpsLearn to read and analyze hex dumps for CTF challenges -- understanding the xxd format, spotting magic bytes, finding hidden strings, and using hex editors to inspect binary files.
What to try next
- Reverse EngineeringMedium
Autorev 1
Timed reverse engineering challenge: quickly identify the correct input or key in the binary before the clock runs out.
- Reverse EngineeringMedium
Bypass Me
Decompile the password-protected binary and find the hardcoded check logic. Patch the comparison or extract the expected value to bypass authentication and read the flag.
- Reverse EngineeringMedium
Gatekeeper
Reverse engineer the binary to discover what numeric property (e.g., prime, perfect, palindrome) the input must satisfy to unlock the flag.
- Reverse EngineeringMedium
Hidden Cipher 1
The flag is right in front of you; just slightly encrypted. Figure out the XOR cipher and the key hidden in this packed binary.
- Reverse EngineeringMedium
Hidden Cipher 2
Solve a math problem to obtain a partial answer, then reverse engineer how that value drives the binary's per-character flag transformation.