Explanation: John will perform OS fingerprinting on the We-are-secure network. Fingerprinting is the easiest way to detect the Operating System (OS) of a remote system. OS detection is important because, after knowing the target system’s OS, it becomes easier to hack into the system. The comparison of data packets that are sent by the target system is done by fingerprinting. The analysis of data packets gives the attacker a hint as to which operating system is being used by the remote system. There are two types of fingerprinting techniques as follows: 1.Active fingerprinting 2.Passive fingerprinting In active fingerprinting ICMP messages are sent to the target system and the response message of the target system shows which OS is being used by the remote system. In passive fingerprinting the number of hops reveals the OS of the remote system. Answer: D and B are incorrect. John should perform OS fingerprinting first, after which it will be easy to identify which services are running on the network since there are many services that run only on a specific operating system. After performing OS fingerprinting, John should perform networking mapping. Answer: C is incorrect. This is a pre-attack phase, and only after gathering all relevant knowledge of a network should John install a backdoor.