Piggybacking refers to access of a wireless Internet connection by bringing one's own computer within the range of another's wireless connection, and using that service without the subscriber's explicit permission or knowledge. It is a legally and ethically controversial practice, with laws that vary in jurisdictions around the world. While completely outlawed in some jurisdictions, it is permitted in others. The process of sending data along with the acknowledgment is called piggybacking. Answer: C is incorrect. Bluebugging is an attack used only in a Bluetooth network. Bluebugging is a form of bluetooth attack often caused by a lack of awareness. Bluebugging tools allow attacker to "take control" of the victim's phone via the usage of the victim's Bluetooth phone headset. It does this by pretending to be the users bluetooth headset and therefore "tricking" the phone to obey its call commands. Answer: D is incorrect. A worm is a software program that uses computer networks and security holes to replicate itself from one computer to another. It usually performs malicious actions, such as using the resources of computers as well as shutting down computers. Answer: B is incorrect. A Denial-of-Service (DoS) attack is mounted with the objective of causing a negative impact on the performance of a computer or network. It is also known as a network saturation attack or bandwidth consumption attack. Attackers perform DoS attacks by sending a large number of protocol packets to the network. The effects of a DoS attack are as follows: Saturates network resources Disrupts connections between two computers, thereby preventing communications between services Disrupts services to a specific computer Causes failure to access a Web site Results in an increase in the amount of spam A Denial-of-Service attack is very common on the Internet because it is much easier to accomplish. Most of the DoS attacks rely on the weaknesses in the TCP/IP protocol.