mirror of
https://github.com/dobin/ShellcodeObfuscationLab
synced 2026-06-08 13:53:31 +00:00
Dobin Rutishauser
47 lines
1.5 KiB
Python
47 lines
1.5 KiB
Python
import sys
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def get_raw_sc(input_file):
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input_file = input_file
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file_shellcode = b''
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try:
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with open(input_file, 'rb') as shellcode_file:
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file_shellcode = shellcode_file.read()
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file_shellcode = file_shellcode.strip()
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return(file_shellcode)
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except FileNotFoundError:
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sys.exit("Supplied input file not found!")
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def offset(input_file):
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# read in our raw shellcode and get the length
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raw_sc = get_raw_sc(input_file)
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sc_len = len(raw_sc)
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offset_arr = [] # stores the calculated offsets
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remaining_idx = 1 # starts at 1 - second byte of shellcode
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previous_byte = raw_sc[0] # Store previous byte we processed.
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# Loop through remaining bytes of shellcode
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while remaining_idx < sc_len:
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# Subtract previous byte from current byte to get the offset
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current_byte = raw_sc[remaining_idx] - previous_byte
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# Add 256 if value is negative to wrap around.
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if current_byte < 0:
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current_byte = current_byte + 256
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# Add current byte of offset array
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offset_arr.append(current_byte)
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# Update previous byte to current shellcode byte
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previous_byte = raw_sc[remaining_idx]
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remaining_idx += 1
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ret = ""
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ret += 'unsigned char first_byte = ' + hex(raw_sc[0]) + ';'
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ret += 'unsigned char delta[{}] = '.format(str(len(offset_arr))) + "{"
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ret += '{}'.format(', '.join((hex(x) for x in offset_arr))) + " };"
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ret += 'unsigned char shellcode[{}] = '.format(str(sc_len)) + '{ 0x00 };'
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return ret
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