CompTIA SY0-401 Free Practice Questions

Answer: C 

Explanation: 

Steganography is the process of concealing a file, message, image, or video within another file, message, image, or video. Note: The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible encrypted messages, no matter how unbreakable will arouse interest, and may in themselves be incriminating in countries where encryption is illegal. Thus, whereas cryptography is the practice of protecting the contents of a message alone, steganography is concerned with concealing the fact that a secret message is being sent, as well as concealing the contents of the message. 

Answer: D 

Explanation: 

Answer: A 

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. 

Answer: B 

Explanation: 

Fuzzing is a software testing technique that involves providing invalid, unexpected, or random data to as inputs to a computer program. The program is then monitored for exceptions such as crashes, or failed validation, or memory leaks. 

Answer: B 

Explanation: 

A zero day vulnerability is an unknown vulnerability in a software application. This cannot be prevented by user security training. 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. 

Answer: C,D 

Explanation: 

With the given subnet mask, a maximum number of 30 hosts between IP addresses 10.4.4.161 and 10.4.4.190 are allowed. Therefore, option C and D would be hosts on the same subnet, and the other options would not. 

References: http://www.subnetonline.com/pages/subnet-calculators/ip-subnet-calculator.php 

Answer: D 

Explanation: 

A mandatory vacation policy requires all users to take time away from work to refresh. Mandatory vacation give the employee a chance to refresh, but it also gives the company a chance to make sure that others can fill in any gaps in skills and satisfies the need to have replication or duplication at all levels. Mandatory vacations also provide an opportunity to discover fraud. In this case mandatory vacations can prevent the two members from colluding to steal the information that they have access to. 

Answer: D 

Explanation: 

Discretionary access control (DAC) allows access to be granted or restricted by an object’s owner based on user identity and on the discretion of the object owner. 

Answer: B 

Explanation: 

Answer: B 

Explanation: 

In cryptography, RC4 is the most widely used software stream cipher and is used in popular Internet protocols such as Transport Layer Security (TLS). While remarkable for its simplicity and speed in software, RC4 has weaknesses that argue against its use in new systems. It is especially vulnerable when the beginning of the output keystream is not discarded, or when nonrandom or related keys are used; some ways of using RC4 can lead to very insecure protocols such as WEP. 

Because RC4 is a stream cipher, it is more malleable than common block ciphers. If not used together with a strong message authentication code (MAC), then encryption is vulnerable to a bit-flipping attack. The cipher is also vulnerable to a stream cipher attack if not implemented correctly. Furthermore, inadvertent double encryption of a message with the same key may accidentally output plaintext rather than ciphertext because the involutory nature of the XOR function would result in the second operation reversing the first. It is noteworthy, however, that RC4, being a stream cipher, was for a period of time the only common cipher that was immune to the 2011 BEAST attack on TLS 1.0. The attack exploits a known weakness in the way cipher block chaining mode is used with all of the other ciphers supported by TLS 1.0, which are all block ciphers. 

Answer: B,C 

Explanation: 

A digital signature is similar in function to a standard signature on a document. It validates the integrity of the message and the sender. The message is encrypted using the encryption system, and a second piece of information, the digital signature, is added to the message. Nonrepudiation prevents one party from denying actions that they carried out and in the electronic world nonrepudiation measures can be a two-key cryptographic system and the involvement of a third party to verify the validity. This respected third party ‘vouches’ for the individuals in the two-key system. Thus non-repudiation also impacts on integrity. 

Answer: A 

Explanation: 

In transitive trusts, trust between a first party and a third party flows through a second party that is trusted by both the first party and the third party. 

Answer: B 

Explanation: 

Answer: B 

Explanation: 

A minimum password age policy defines the period that a password must be used for before it can be changed. 

Answer: C 

Explanation: 

DNS operates over TCP and UDP port 53. TCP port 53 is used for zone transfers.