Problem 4 –Extract opcode

1. Create the following hellorelative.nasm code

2. Use nasm to generate the object file hello.o

3. Use the debugger to find the relative address that contains the string hello_world. 

4. Use objdump -d hello.o to display the opcode

5. Use the following regular expressions to extract the opcode (shellcode) from objdump as follows:

Objdump –D –M intel hello.o | grep ‘[0-9a-f]:’  | cut –c7-26 | paste –d ‘   ’  -s 

| tr –s  ‘   ’ ‘   ’| sed  ‘s/ /\\x/g’ | sed ‘s/\\x$//’ | sed s’/55/\\x55/’  > shellcode

6. Attach the opcode and the extracted opcode(shellcode)