I am taking the same class and I can tell you how I did this problem. I saw your name in the offensive-security forums few times. if you did not solve this as yet email me (busnan100@yahoo.com).

Jack

I am currently taking this course and indeed it is an excellent course. I am having problem completing exercise 23 & final challenge. If any who has taken this course would like to share information regarding these two exercises, I have enclosed my email below.

Jack

busana100@yahoo.com