CompTIA Security+ Question L-62

Which of the following should a company implement to BEST mitigate from zero-day malicious code executing on employees’ computers?

A. Least privilege accounts
B. Host-based firewalls
C. Intrusion Detection Systems
D. Application whitelisting

Answer: D

Explanation:
Application whitelisting is a security stance that prohibits unauthorized software from being able to execute unless it is on the preapproved exception list: the whitelist. This prevents any and all software, including malware, from executing unless it is on the whitelist. This can help block zero-day attacks, which are new attacks that exploit flaws or vulnerabilities in targeted systems and applications that are unknown or undisclosed to the world in general.

CompTIA Security+ Question K-61

An auditor is given access to a conference room to conduct an analysis. When they connect their laptop’s Ethernet cable into the wall jack, they are not able to get a connection to the Internet but have a link light. Which of the following is MOST likely causing this issue?

A. Ethernet cable is damaged
B. The host firewall is set to disallow outbound connections
C. Network Access Control
D. The switch port is administratively shutdown

Answer: C

Explanation:
Network Access Control (NAC) means controlling access to an environment through strict adherence to and implementation of security policies. The goals of NAC are to prevent/reduce zero-day attacks, enforce security policy throughout the network, and use identities to perform access control.

CompTIA Security+ Question J-66

A computer is put into a restricted VLAN until the computer’s virus definitions are up-to-date.
Which of the following BEST describes this system type?

A. NAT
B. NIPS
C. NAC
D. DMZ

Answer: C

Explanation:
Network Access Control (NAC) means controlling access to an environment through strict adherence to and implementation of security policies. The goals of NAC are to prevent/reduce zero-day attacks, enforce security policy throughout the network, and use identities to perform access control.

CompTIA Security+ Question I-31

A security administrator wants to get a real time look at what attackers are doing in the wild, hoping to lower the risk of zero-day attacks. Which of the following should be used to accomplish this goal?

A. Penetration testing
B. Honeynets
C. Vulnerability scanning
D. Baseline reporting

Answer: B

Explanation:
A honeynet is a network set up with intentional vulnerabilities; its purpose is to invite attack, so that an attacker’s activities and methods can be studied and that information used to increase network security. A honeynet contains one or more honey pots, which are computer systems on the Internet expressly set up to attract and “trap” people who attempt to penetrate other people’s computer systems. Although the primary purpose of a honeynet is to gather information about attackers’ methods and motives, the decoy network can benefit its operator in other ways, for example by diverting attackers from a real network and its resources. The Honeynet Project, a non-profit research organization dedicated to computer security and information sharing, actively promotes the deployment of honeynets. In addition to the honey pots, a honeynet usually has real applications and services so that it seems like a normal network and a worthwhile target. However, because the honeynet doesn’t actually serve any authorized users, any attempt to contact the network from without is likely an illicit attempt to breach its security, and any outbound activity is likely evidence that a system has been compromised. For this reason, the suspect information is much more apparent than it would be in an actual network, where it would have to be found amidst all the legitimate network data. Applications within a honeynet are often given names such as “Finances” or “Human Services” to make them sound appealing to the attacker.

A virtual honeynet is one that, while appearing to be an entire network, resides on a single server.

CompTIA Security+ Question H-53

The security administrator is observing unusual network behavior from a workstation. The workstation is communicating with a known malicious destination over an encrypted tunnel. A full antivirus scan, with an updated antivirus definition file, does not show any signs of infection.
Which of the following has happened on the workstation?

A. Zero-day attack
B. Known malware infection
C. Session hijacking
D. Cookie stealing

Answer: A

Explanation:
The vulnerability was unknown in that the full antivirus scan did not detect it. This is zero day vulnerability. A zero day vulnerability refers to a hole in software that is unknown to the vendor. This security hole is then exploited by hackers before the vendor becomes aware and hurries to fix it—this exploit is called a zero day attack. Uses of zero day attacks can include infiltrating malware, spyware or allowing unwanted access to user information. The term “zero day” refers to the unknown nature of the hole to those outside of the hackers, specifically, the developers. Once the vulnerability becomes known, a race begins for the developer, who must protect users.

CompTIA Security+ Question F-61

A security administrator is investigating a recent server breach. The breach occurred as a result of a zero-day attack against a user program running on the server. Which of the following logs should the administrator search for information regarding the breach?

A. Application log
B. Setup log
C. Authentication log
D. System log

Answer: A

CompTIA Security+ Question A-39

Matt, an IT administrator, wants to protect a newly built server from zero day attacks. Which of the following would provide the BEST level of protection?

A. HIPS
B. Antivirus
C. NIDS
D. ACL

Answer: A

Explanation:
Intrusion prevention systems (IPS), also known as intrusion detection and prevention systems (IDPS), are network security appliances that monitor network and/or system activities for malicious activity. The main functions of intrusion prevention systems are to identify malicious activity, log information about this activity, attempt to block/stop it, and report it.

Intrusion prevention systems are considered extensions of intrusion detection systems because they both monitor network traffic and/or system activities for malicious activity. The main differences are, unlike intrusion detection systems, intrusion prevention systems are placed in-line and are able to actively prevent/block intrusions that are detected. More specifically, IPS can take such actions as sending an alarm, dropping the malicious packets, resetting the connection and/or blocking the traffic from the offending IP address. An IPS can also correct Cyclic Redundancy Check (CRC) errors, unfragment packet streams, prevent TCP sequencing issues, and clean up unwanted transport and network layer options. Host-based intrusion prevention system (HIPS) is an installed software package which monitors a single host for suspicious activity by analyzing events occurring within that host. A Host-based intrusion prevention system (HIPS) is an installed software package which monitors a single host for suspicious activity by analyzing events occurring within that host. As a zero-day attack is an unknown vulnerability (a vulnerability that does not have a fix or a patch to prevent it), the best defence would be an intrusion prevention system.

CompTIA Network+ Question C-84

A network administrator receives a call asking for assistance with connecting to the network. The user asks for the IP address, subnet class, and VLAN required to access the network. This describes which of the following attacks?

A. Social engineering
B. Spoofing
C. Zero-day attack
D. VLAN hopping

Correct Answer: A

CompTIA Network+ Question B-83

Exploiting a weakness in a user’s wireless headset to compromise the mobile device is known as which of the following?

A. Multiplexing
B. Zero-day attack
C. Smurfing
D. Bluejacking

Correct Answer: D