Which of the following steps are required in an idle scan of a closed port? Each correct answer represents a part of the solution. Choose all that apply.
Correct Answer: A,B,C,D
Following are the steps required in an idle scan of a closed port: 1.Probe the zombie's IP ID: The attacker sends a SYN/ACK to the zombie. The zombie, unaware of the SYN/ ACK, sends back a RST, thus disclosing its IP ID. 2.Forge a SYN packet from the zombie: In response to the SYN, the target sends a RST. The zombie ignores the unsolicited RST, and the IP ID remains unchanged. 3.Probe the zombie's IP ID again: The zombie's IP ID has increased by only 1 since step 1. So the port is closed.
Question 102
An employee of a medical service company clicked a malicious link in an email sent by an attacker. Suddenly, employees of the company are not able to access billing information or client record as it is encrypted. The attacker asked the company to pay money for gaining access to their dat a. Which type of malware attack is described above?
Correct Answer: B
Question 103
Which of the following provide an "always on" Internet access service when connecting to an ISP?Each correct answer represents a complete solution. Choose two.
Correct Answer: B,D
DSL and Cable modems are used in remote-access WAN technology for connecting to the Internet. Both provide an "always on" Internet access service. Answer options C and A are incorrect. Analog and Digital modems are not always in 'ON' mode when connecting to an ISP. Analog modems transmit analog voice signals, while Digital modems transmit digital signals over a link.
Question 104
Identify the password cracking attempt involving precomputed hash values stored as plaintext and using these to crack the password.
Correct Answer: D
Question 105
Which of the following OSI layers establishes, manages, and terminates the connections between the local and remote applications?
Correct Answer: D
The session layer of the OSI/RM controls the dialogues (connections) between computers. It establishes, manages and terminates the connections between the local and remote application. It provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. The OSI model made this layer responsible for graceful close of sessions, which is a property of the Transmission Control Protocol, and also for session checkpointing and recovery, which is not usually used in the Internet Protocol Suite. The Session Layer is commonly implemented explicitly in application environments that use remote procedure calls. Answer option C is incorrect. The Application Layer of TCP/IP model refers to the higher-level protocols used by most applications for network communication. Examples of application layer protocols include the File Transfer Protocol (FTP) and the Simple Mail Transfer Protocol (SMTP). Data coded according to application layer protocols are then encapsulated into one or more transport layer protocols, which in turn use lower layer protocols to affect actual data transfer. Answer option A is incorrect. The Data Link Layer is Layer 2 of the seven-layer OSI model of computer networking. It corresponds to or is part of the link layer of the TCP/IP reference model. The Data Link Layer is the protocol layer which transfers data between adjacent network nodes in a wide area network or between nodes on the same local area network segment. The Data Link Layer provides the functional and procedural means to transfer data between network entities and might provide the means to detect and possibly correct errors that may occur in the Physical Layer. Examples of data link protocols are Ethernet for local area networks (multi-node), the Point-to-Point Protocol (PPP), HDLC, and ADCCP for point-to-point (dual-node) connections. Answer option B is incorrect. The network layer controls the operation of subnet, deciding which physical path the data should take, based on network conditions, priority of service, and other factors. Routers work on the Network layer of the OSI stack.
