John works as a professional Ethical Hacker.

Web ripping is a technique in which the attacker copies the whole structure of a Web site to the local disk and obtains all files of the Web site. Web ripping helps an attacker to trace the loopholes of the Web site. Answer: A is incorrect. Eavesdropping is the intentional interception of data (such as e-mail, username, password, credit card, or calling card number) as it passes from a user's computer to a server, or vice versa. There are high-tech methods of eavesdropping. It has been demonstrated that a laser can be bounced off a window and vibrations caused by the sounds inside the building can be collected and turned back into those sounds. The cost of high-tech surveillance has made such instruments available only to the professional information gatherer, however. But as with all high-tech electronics, falling prices are making these more affordable to a wider audience.

Answer: D is incorrect. In TCP FTP proxy (bounce attack) scanning, a scanner connects to an FTP server and requests it to start data transfer to a third system. The scanner uses the PORT FTP command to find out whether or not the data transfer process is listening to the target system at a certain port number. It then uses the LIST FTP command to list the current directory, and the result is sent over the server. If the data transfer is successful, it clearly indicates that the port is open. If the port is closed, the attacker receives the connection refused ICMP error message. Answer: B is incorrect. 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.