Reverse Engineering Notes
Table of Contents
file: Identify file type and format.strings: Extract readable strings from executables.checksec: Analyze security features of binaries.readelf: Retrieve metadata from ELF files.objdump: Disassemble and inspect object files.hexeditor: Modify binary files at the hex level.ltrace and strace: Trace library and system calls.nm: List symbols from object files.patchelf: Modify ELF binaries.capstone: Disassembly framework.keystone: Assembly framework.unicorn: Emulation framework.
Test Environments
Terminologies
- Machine Code: Low-level binary instructions executed by the CPU.
- Assembly: Human-readable representation of machine code.
- Executable: A compiled binary file ready to be executed.
- Compiler: Translates source code into machine code.
- Debugger: A tool to analyze and manipulate program execution.
- Disassembler: Converts machine code into assembly.
- Decompiler: Converts binary code back into high-level code.
- Static Analysis: Examining binaries without executing them.
- Dynamic Analysis: Analyzing binaries by executing them in a controlled environment.
- Symbolic Execution: Analyzing programs by following all possible execution paths.
- ROP (Return Oriented Programming): Exploiting return instructions to gain control.
- Heap Overflow: Exploiting memory mismanagement in heap.
- Stack Overflow: Overwriting return addresses in stack memory.
- Format String Vulnerability: Exploiting uncontrolled format string inputs.
- Code Obfuscation: Techniques to make binary analysis harder.
- Reversing Malware: Analyzing malicious binaries to understand behavior.
- Encryption & Encoding: Methods to obscure data within binaries.
- Packed Executables: Binaries modified to hide code until execution.
- Hooking: Intercepting function calls or system events for analysis or modification.
- Debug Symbols: Additional information in binaries to aid debugging.
- Syscalls: Direct interactions with the operating system’s kernel.
Notes
- PE Sections:
- .text: Code.
- .data: Initialized variables.
- .rdata: Read-only data.
- ELF Sections:
- .text: Code.
- .bss: Uninitialized data.
- .plt and .got: Dynamic linking.
- Understanding Protections:
- ASLR (Address Space Layout Randomization): Randomizes memory locations.
- Bypass: Use information leaks.
- DEP (Data Execution Prevention): Prevents execution of non-code memory.
- Bypass: Use return-oriented programming (ROP).
- Obfuscation: Hides program logic.
- Bypass: Deobfuscate by analyzing patterns.
Exploitation Techniques
- Stack-based Buffer Overflow: Overwriting return addresses to hijack execution.
- Heap-based Exploitation: Manipulating dynamic memory allocation for control.
- Integer Overflow: Exploiting arithmetic errors to bypass security checks.
- Format String Exploits: Leaking memory or modifying execution flow via uncontrolled format strings.
- Return to Libc: Calling existing library functions to execute arbitrary code.
- ROP (Return Oriented Programming): Chaining gadgets to execute arbitrary instructions.
- JOP (Jump Oriented Programming): Similar to ROP but using jump instructions.
- GOT Overwrite: Modifying function pointers in the Global Offset Table to redirect execution.
- PLT Hijacking: Exploiting the Procedure Linkage Table to control execution flow.
- Code Injection: Injecting shellcode into a process and executing it.
- Sandbox Evasion: Bypassing restricted execution environments.
- Symbol Resolution Exploits: Manipulating dynamic linking to execute unintended code.
Labs
Videos and Articles