Breaking Down the China Chopper Web Shell – Part I
https://www.fireeye.com/blog/threat-research/2013/08/breaking-down-the-china-chopper-web-shell-part-i.html

tshark – Dump and analyze network traffic
https://www.wireshark.org/docs/man-pages/tshark.html

netsniff-ng toolkit
http://netsniff-ng.org/

Nmap Cheat Sheet > Service and OS Detection
https://hackertarget.com/nmap-cheatsheet-a-quick-reference-guide/