how to send a corrupt netbios packet

I want to send a corrupt netbios Session Service packet to my machine, My goal it to check whether my machine restarts or not upon receiving the corrupt netbios packet (this has happened before and I want to reproduce the same).

I am using scapy which is a python tool to establish a connection first to the machine at port 139 and then I am sending a NBTSession() packet to the machine.

In the wireshark traces I see that the session is established, but when I am trying to send a packet with NBTSession() layer then the wireshark traces shows its a NBSS continuation message.

from scapy.all import *

def nbt_func():
        nb=NBTSession(TYPE=0x81,RESERVED=10,LENGTH=2000)
        rnb=Raw(nb)
        s=socket.socket()
        s.connect(("10.62.147.30",139))
        ss=StreamSocket(s,Raw)
        s.sr1(rnb)

if __name__ == "__main__":
        nbt_func()

Any idea why this is happening, or is there any other way the issue can be reproduced?

I gave some random values in the NBTSession() fields as I thought that maybe giving wrong values means corrupting the packet.

Thanks for the help.

Solution 1:

Corrupt packages are not exactly formatted on layer 5+ :) It could be even a corrupted IP header, so you cannot create a corrupted package using high-level libraries.

A good approach a can propose - is to connect to your server with netcat and send some garbage from /dev/urandom:

cat /dev/urandom | nc 10.62.147.30 139