Please enable JavaScript.

Coggle requires JavaScript to display documents.

Hacking 101 (Native Code crash course, Advanced) (Computer Architecture…

- - - - Physical Memory
        
        RAM
        
        Address from 0
        
        Eg. 64MB of ram
        
        Lowest (0x00000000)
        Highest (0x03FFFFFF)
        
        App running on modern OS
        
        no direct access
        
        be able to read/write memory
        for other program
      - Virtual Memory
        
        abstraction
        (Allows you to use normal applications to
        access memory)
        
        processes are separated and
        how we share code btw processes
        
        heart
        
        page table
        
        split address space into series of pages
        
        either unmapped / point to physical memory address
        
        each page
        
        permission
        
        read
        
        write
        
        execute
        
        stack
        
        local variables of a function
        
        grow down
        
        calla function
        
        create a new "stack frame"
        
        store previous stack pointer somewhere
        
        substract from, give yourself some space
        
        to store data required
        
        Once done
        
        restore original stack pointer
    - - Executed in the context of registers
        
        Reading / writing
  - - - why
        
        memory accessed
        
        8-bit (bytes)
        
        most numbers
        
        16 bit
        
        32 bit
        
        64 bit
    - - little
        
        0x01ab23cd
      - big
        
        store the most significant
  - - - stack / specific registar
        
        call a subroutine (function)
        
        once done
        
        return function
        
        set program to counter back
        store address
  - - - tell kernal
        
        perform operation
        
        reading / writing
        
        sending / receiving network data
        
        launching other applications
        
        kernal
        
        core part of an op system
        
        resource allocation
        
        file management
        
        security
  - - - main binary
        
        static linking
    - - dynamic linking
        
        call out to other libaries
      - load plugins
  - - - GUI -based
      - allow you to browse through code
        
        annotate
        
        giving subroutine name
      - non
        
        text-listing code
      - Examples
        
        IDA Pro
        
        gold standard , ex
        
        Hopper
        
        gd for MacOS and IOS apps
        
        Ghidra
        
        NSA open sourse tool, a bit buggy
  - - - assembly code
        
        convert to machine code
        
        done to prod small patches
        
        shell storm
  - - - inside binary
      - 0xED
      - HxD
- - - - advantageous way
  - - - not properly handled
      - memory allocated for obj
        
        info leaks
        
        arbitrary writes
        
        direct code execution
- - - - put random (known) value
    - - check if value is still right
  - - - executable
      - readable
        
        executable
      - allowing pages
        
        marked as code
        
        executed
  - - - at runtime
      - eg browser compiling jS to machine code
        
        for performance
        
        attacker write their own code
        
        jump on it
  - - - process address space
        
        randomized at location
      - binary & shared libraries
        
        random base address
    - - 10-16 bits of randomness
      - 1024-65536 possible base address
    - - 16-24 bits
        
        16 million possible
    - - info leaks