Which of the following is an attack on a website that changes the visual appearance of the site and seriously damages the trust and reputation of the website?
Correct Answer: A
Website defacement is an attack on a website that changes the visual appearance of the site. These are typically the work of system crackers, who break into a Web server and replace the hosted website with one of their own. Sometimes, the Defacer makes fun of the system administrator for failing to maintain server security. Most times, the defacement is harmless; however, it can sometimes be used as a distraction to cover up more sinister actions such as uploading malware. A high-profile website defacement was carried out on the website of the company SCO Group following its assertion that Linux contained stolen code. The title of the page was changed from Red Hat vs. SCO to SCO vs. World with various satirical content. Answer option D is incorrect. Buffer overflow is a condition in which an application receives more data than it is configured to accept. This usually occurs due to programming errors in the application. Buffer overflow can terminate or crash the application. Answer option B is incorrect. A zero-day attack, also known as zero-hour attack, is a computer threat that tries to exploit computer application vulnerabilities which are unknown to others, undisclosed to the software vendor, or for which no security fix is available. Zero-day exploits (actual code that can use a security hole to carry out an attack) are used or shared by attackers before the software vendor knows about the vulnerability. User awareness training is the most effective technique to mitigate such attacks. Answer option C is incorrect. Spoofing is a technique that makes a transmission appear to have come from an authentic source by forging the IP address, email address, caller ID, etc. In IP spoofing, a hacker modifies packet headers by using someone else's IP address to hide his identity. However, spoofing cannot be used while surfing the Internet, chatting on-line, etc. because forging the source IP address causes the responses to be misdirected.
Question 77
Which of the following is a compatible network device that converts various communication protocols and are used to connect different network technologies?
Correct Answer: B
Question 78
Which of the following is an intrusion detection system that reads all incoming packets and tries to find suspicious patterns known as signatures or rules?
Correct Answer: D
A network intrusion detection system (NIDS) is an intrusion detection system that tries to detect malicious activity such as denial of service attacks, port scans or even attempts to crack into computers by monitoring network traffic. A NIDS reads all the incoming packets and tries to find suspicious patterns known as signatures or rules. It also tries to detect incoming shell codes in the same manner that an ordinary intrusion detection system does. Answer option A is incorrect. A host-based intrusion detection system (HIDS) produces a false alarm because of the abnormal behavior of users and the network. A host-based intrusion detection system (HIDS) is an intrusion detection system that monitors and analyses the internals of a computing system rather than the network packets on its external interfaces. A host-based Intrusion Detection System (HIDS) monitors all or parts of the dynamic behavior and the state of a computer system. HIDS looks at the state of a system, its stored information, whether in RAM, in the file system, log files or elsewhere; and checks that the contents of these appear as expected. Answer option B is incorrect. An intrusion prevention system (IPS) is a network security device that monitors network and/or system activities for malicious or unwanted behavior and can react, in real-time, to block or prevent those activities. When an attack is detected, it can drop the offending packets while still allowing all other traffic to pass. Answer option C is incorrect. A demilitarized zone (DMZ) is a physical or logical subnetwork that contains and exposes external services of an organization to a larger network, usually the Internet. The purpose of a DMZ is to add an additional layer of security to an organization's Local Area Network (LAN); an external attacker only has access to equipment in the DMZ, rather than the whole of the network. Hosts in the DMZ have limited connectivity to specific hosts in the internal network, though communication with other hosts in the DMZ and to the external network is allowed. This allows hosts in the DMZ to provide services to both the internal and external networks, while an intervening firewall controls the traffic between the DMZ servers and the internal network clients. In a DMZ configuration, most computers on the LAN run behind a firewall connected to a public network such as the Internet.
Question 79
Which of the following is a term to describe the use of inert gases and chemical agents to extinguish a fire?
Correct Answer: C
Question 80
Which of the following statements are true about volatile memory?Each correct answer represents a complete solution. Choose all that apply.
Correct Answer: C,D
Volatile memory, also known as volatile storage, is computer memory that requires power to maintain the stored information, unlike non-volatile memory which does not require a maintained power supply. It has been less popularly known as temporary memory. Most forms of modern random access memory (RAM) are volatile storage, including dynamic random access memory (DRAM) and static random access memory (SRAM). A volatile storage device is faster in reading and writing data.Answer options B and A are incorrect. Non-volatile memory, nonvolatile memory, NVM, or non-volatile storage, in the most basic sense, is computer memory that can retain the stored information even when not powered. Examples of non-volatile memory include read-only memory, flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy disks, and magnetic tape), optical discs, and early computer storage methods such as paper tape and punched cards.