CompTIA Security+ Question K-85

Four weeks ago, a network administrator applied a new IDS and allowed it to gather baseline data. As rumors of a layoff began to spread, the IDS alerted the network administrator that access to sensitive client files had risen far above normal. Which of the following kind of IDS is in use?

A. Protocol based
B. Heuristic based
C. Signature based
D. Anomaly based

Answer: D

Explanation:
Most intrusion detection systems (IDS) are what is known as signature-based. This means that they operate in much the same way as a virus scanner, by searching for a known identity – or signature – for each specific intrusion event. And, while signature-based IDS is very efficient at sniffing out known methods of attack, it does, like anti-virus software, depend on receiving regular signature updates, to keep in touch with variations in hacker technique. In other words, signature-based IDS is only as good as its database of stored signatures. Any organization wanting to implement a more thorough – and hence safer – solution, should consider what we call anomaly-based IDS. By its nature, anomaly-based IDS is a rather more complex creature. In network traffic terms, it captures all the headers of the IP packets running towards the network. From this, it filters out all known and legal traffic, including web traffic to the organization’s web server, mail traffic to and from its mail server, outgoing web traffic from company employees and DNS traffic to and from its DNS server.

There are other equally obvious advantages to using anomaly-based IDS. For example, because it detects any traffic that is new or unusual, the anomaly method is particularly good at identifying sweeps and probes towards network hardware. It can, therefore, give early warnings of potential intrusions, because probes and scans are the predecessors of all attacks. And this applies equally to any new service installed on any item of hardware – for example, Telnet deployed on a network router for maintenance purposes and forgotten about when the maintenance was finished. This makes anomaly-based IDS perfect for detecting anything from port anomalies and web anomalies to mis-formed attacks, where the URL is deliberately mis-typed.

CompTIA Security+ Question H-82

Suspicious traffic without a specific signature was detected. Under further investigation, it was determined that these were false indicators. Which of the following security devices needs to be configured to disable future false alarms?

A. Signature based IPS
B. Signature based IDS
C. Application based IPS
D. Anomaly based IDS

Answer: D

Explanation:
Most intrusion detection systems (IDS) are what is known as signature-based. This means that they operate in much the same way as a virus scanner, by searching for a known identity – or signature – for each specific intrusion event. And, while signature-based IDS is very efficient at sniffing out known s of attack, it does, like anti-virus software, depend on receiving regular signature updates, to keep in touch with variations in hacker technique. In other words, signature-based IDS is only as good as its database of stored signatures. Any organization wanting to implement a more thorough – and hence safer – solution, should consider what we call anomaly-based IDS. By its nature, anomaly-based IDS is a rather more complex creature. In network traffic terms, it captures all the headers of the IP packets running towards the network. From this, it filters out all known and legal traffic, including web traffic to the organization’s web server, mail traffic to and from its mail server, outgoing web traffic from company employees and DNS traffic to and from its DNS server.

There are other equally obvious advantages to using anomaly-based IDS. For example, because it detects any traffic that is new or unusual, the anomaly method is particularly good at identifying sweeps and probes towards network hardware. It can, therefore, give early warnings of potential intrusions, because probes and scans are the predecessors of all attacks. And this applies equally to any new service installed on any item of hardware – for example, Telnet deployed on a network router for maintenance purposes and forgotten about when the maintenance was finished. This makes anomaly-based IDS perfect for detecting anything from port anomalies and web anomalies to mis-formed attacks, where the URL is deliberately mis-typed.

CompTIA Security+ Question F-12

The network security engineer just deployed an IDS on the network, but the Chief Technical Officer (CTO) has concerns that the device is only able to detect known anomalies. Which of the following types of IDS has been deployed?

A. Signature Based IDS
B. Heuristic IDS
C. Behavior Based IDS
D. Anomaly Based IDS

Answer: A

Explanation:
A signature based IDS will monitor packets on the network and compare them against a database of signatures or attributes from known malicious threats.

CompTIA Security+ Question C-12

When performing the daily review of the system vulnerability scans of the network Peter, the administrator, noticed several security related vulnerabilities with an assigned vulnerability identification number. Peter researches the assigned vulnerability identification number from the vendor website. Peter proceeds with applying the recommended solution for identified vulnerability.
Which of the following is the type of vulnerability described?

A. Network based
B. IDS
C. Signature based
D. Host based

Answer: C

Explanation:
A signature-based monitoring or detection method relies on a database of signatures or patterns of known malicious or unwanted activity. The strength of a signature-based system is that it can quickly and accurately detect any event from its database of signatures.

CompTIA Security+ Question A-50

Using a heuristic system to detect an anomaly in a computer’s baseline, a system administrator was able to detect an attack even though the company signature based IDS and antivirus did not detect it. Further analysis revealed that the attacker had downloaded an executable file onto the company PC from the USB port, and executed it to trigger a privilege escalation flaw.
Which of the following attacks has MOST likely occurred?

A. Cookie stealing
B. Zero-day
C. Directory traversal
D. XML injection

Answer: B

Explanation:
The vulnerability was unknown in that the IDS and antivirus 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 Network+ Question B-95

A technician needs to install software onto company laptops to protect local running services, from external threats. Which of the following should the technician install and configure on the laptops if the threat is network based?

A. A cloud-based antivirus system with a heuristic and signature based engine
B. A network based firewall which blocks all inbound communication
C. A host-based firewall which allows all outbound communication
D. A HIDS to inspect both inbound and outbound network communication

Correct Answer: C

Explanation:
A host-based firewall is a computer running firewall software that can protect the computer itself. For example, it can prevent incoming connections to the computer and allow outbound communication only.