- (Topic 6)
Which of the following is the most secure firewall implementation?
Correct Answer:
B
One the most secure implementations of firewall architectures is the screened-subnet firewall. It employs two packet-filtering routers and a bastion host. Like a screened host firewall, this firewall supports both packet-filtering and proxy services. Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 93).
- (Topic 3)
Which of the following best describes signature-based detection?
Correct Answer:
C
Misuse detectors compare system activity, looking for events or sets of events that match a predefined pattern of events that describe a known attack. As the patterns corresponding to known attacks are called signatures, misuse detection is sometimes called "signature-based detection."
The most common form of misuse detection used in commercial products specifies each pattern of events corresponding to an attack as a separate signature. However, there are more sophisticated approaches to doing misuse detection (called "state-based" analysis techniques) that can leverage a single signature to detect groups of attacks.
Reference:
Old Document:
BACE, Rebecca & MELL, Peter, NIST Special Publication 800-31 on Intrusion Detection Systems, Page 16.
The publication above has been replaced by 800-94 on page 2-4
The Updated URL is: http://csrc.nist.gov/publications/nistpubs/800-94/SP800-94.pdf
- (Topic 7)
What is malware that can spread itself over open network connections?
Correct Answer:
A
Computer worms are also known as Network Mobile Code, or a virus-like bit of code that can replicate itself over a network, infecting adjacent computers.
A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.
A notable example is the SQL Slammer computer worm that spread globally in ten minutes on January 25, 2003. I myself came to work that day as a software tester and found all my SQL servers infected and actively trying to infect other computers on the test network.
A patch had been released a year prior by Microsoft and if systems were not patched and exposed to a 376 byte UDP packet from an infected host then system would become compromised.
Ordinarily, infected computers are not to be trusted and must be rebuilt from scratch but the vulnerability could be mitigated by replacing a single vulnerable dll called sqlsort.dll.
Replacing that with the patched version completely disabled the worm which really illustrates to us the importance of actively patching our systems against such network mobile code.
The following answers are incorrect:
- Rootkit: Sorry, this isn't correct because a rootkit isn't ordinarily classified as network mobile code like a worm is. This isn't to say that a rootkit couldn't be included in a worm, just that a rootkit isn't usually classified like a worm. A rootkit is a stealthy type of software, typically malicious, designed to hide the existence of certain processes or programs from normal methods of detection and enable continued privileged access to a computer. The term rootkit is a concatenation of "root" (the traditional name of the privileged account on Unix operating systems) and the word "kit" (which refers to the software components that implement the tool). The term "rootkit" has negative connotations through its association with malware.
- Adware: Incorrect answer. Sorry but adware isn't usually classified as a worm. Adware, or advertising-supported software, is any software package which automatically renders advertisements in order to generate revenue for its author. The advertisements may be in the user interface of the software or on a screen presented to the user during the installation process. The functions may be designed to analyze which Internet sites the user visits and to present advertising pertinent to the types of goods or services featured there. The term is sometimes used to refer to software that displays unwanted advertisements.
- Logic Bomb: Logic bombs like adware or rootkits could be spread by worms if they exploit the right service and gain root or admin access on a computer.
The following reference(s) was used to create this question: The CCCure CompTIA Holistic Security+ Tutorial and CBT
and
http://en.wikipedia.org/wiki/Rootkit and
http://en.wikipedia.org/wiki/Computer_worm and
http://en.wikipedia.org/wiki/Adware
- (Topic 6)
Which of the following is less likely to be used today in creating a Virtual Private Network?
Correct Answer:
D
L2F (Layer 2 Forwarding) provides no authentication or encryption. It is a Protocol that supports the creation of secure virtual private dial-up networks over the Internet.
At one point L2F was merged with PPTP to produce L2TP to be used on networks and not only on dial up links.
IPSec is now considered the best VPN solution for IP environments.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw- Hill/Osborne, 2002, Chapter 8: Cryptography (page 507).
- (Topic 2)
Which of the following is NOT an example of an operational control?
Correct Answer:
B
Operational controls are controls over the hardware, the media used and the operators using these resources.
Operational controls are controls that are implemented and executed by people, they are most often procedures.
Backup and recovery, contingency planning and operations procedures are operational controls.
Auditing is considered an Administrative / detective control. However the actual auditing mechanisms in place on the systems would be consider operational controls.
