CompTIA Security+ Question L-8

A server with the IP address of 10.10.2.4 has been having intermittent connection issues. The logs show repeated connection attempts from the following IPs:
10.10.3.16
10.10.3.23
212.178.24.26
217.24.94.83
These attempts are overloading the server to the point that it cannot respond to traffic. Which of the following attacks is occurring?

A. XSS
B. DDoS
C. DoS
D. Xmas

Answer: B

Explanation:
A Distributed Denial of Service (DDoS) attack is an attack from several different computers targeting a single computer. One common method of attack involves saturating the target machine with external communications requests, so much so that it cannot respond to legitimate traffic, or responds so slowly as to be rendered essentially unavailable. Such attacks usually lead to a server overload.

A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. Such an attack is often the result of multiple compromised systems (for example a botnet) flooding the targeted system with traffic. When a server is overloaded with connections, new connections can no longer be accepted. The major advantages to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine, and that the behavior of each attack machine can be stealthier, making it harder to track and shut down. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. This after all will end up completely crashing a website for periods of time. Malware can carry DDoS attack mechanisms; one of the better-known examples of this was MyDoom. Its DoS mechanism was triggered on a specific date and time. This type of DDoS involved hardcoding the target IP address prior to release of the malware and no further interaction was necessary to launch the attack.

CompTIA Security+ Question L-4

An administrator is investigating a system that may potentially be compromised, and sees the following log entries on the router.
*Jul 15 14:47:29.779:%Router1: list 101 permitted tcp 192.10.3.204(57222) (FastEthernet 0/3) ->
10.10.1.5 (6667), 3 packets.
*Jul 15 14:47:38.779:%Router1: list 101 permitted tcp 192.10.3.204(57222) (FastEthernet 0/3) ->
10.10.1.5 (6667), 6 packets.
*Jul 15 14:47:45.779:%Router1: list 101 permitted tcp 192.10.3.204(57222) (FastEthernet 0/3) ->
10.10.1.5 (6667), 8 packets.
Which of the following BEST describes the compromised system?

A. It is running a rogue web server
B. It is being used in a man-in-the-middle attack
C. It is participating in a botnet
D. It is an ARP poisoning attack

Answer: C

Explanation:
In this question, we have a source computer (192.10.3.204) sending data to a single destination IP address 10.10.1.5. No data is being received back by source computer which suggests the data being sent is some kind of Denial-of-service attack. This is common practice for computers participating in a botnet. The port used is TCP 6667 which is IRC (Internet Relay Chat). This port is used by many Trojans and is commonly used for DoS attacks.

Software running on infected computers called zombies is often known as a botnet. Bots, by themselves, are but a form of software that runs automatically and autonomously. (For example, Google uses the Googlebot to find web pages and bring back values for the index.) Botnet, however, has come to be the word used to describe malicious software running on a zombie and under the control of a bot-herder. Denial-of-service attacks—DoS and DDoS—can be launched by botnets, as can many forms of adware, spyware, and spam (via spambots). Most bots are written to run in the background with no visible evidence of their presence. Many malware kits can be used to create botnets and modify existing ones.

CompTIA Security+ Question K-93

A technician wants to verify the authenticity of the system files of a potentially compromised system. Which of the following can the technician use to verify if a system file was compromised? (Select TWO).

A. AES
B. PGP
C. SHA
D. MD5
E. ECDHE

Answer: C,D

Explanation:
Hashing is used to prove the integrity of data to prove that it hasn’t been modified. Hashing algorithms are used to derive a key mathematically from a message. The most common hashing standards for cryptographic applications are the SHA and MD algorithms.

CompTIA Security+ Question K-26

A company executive’s laptop was compromised, leading to a security breach. The laptop was placed into storage by a junior system administrator and was subsequently wiped and re-imaged. When it was determined that the authorities would need to be involved, there was little evidence to present to the investigators. Which of the following procedures could have been implemented to aid the authorities in their investigation?

A. A comparison should have been created from the original system’s file hashes
B. Witness testimony should have been taken by the administrator
C. The company should have established a chain of custody tracking the laptop
D. A system image should have been created and stored

Answer: D

Explanation:
A system image is a snapshot of what it and if a system image of the compromised system was created and stored, it is a useful tool when the authorities want to revisit the issue to investigate the incident.

CompTIA Security+ Question H-73

An administrator is assigned to monitor servers in a data center. A web server connected to the Internet suddenly experiences a large spike in CPU activity. Which of the following is the MOST likely cause?

A. Spyware
B. Trojan
C. Privilege escalation
D. DoS

Answer: D

Explanation:
A Distributed Denial of Service (DDoS) attack is a DoS attack from multiple computers whereas a DoS attack is from a single computer. In terms of the actual method of attack, DDoS and DoS attacks are the same. One common method of attack involves saturating the target machine with external communications requests, so much so that it cannot respond to legitimate traffic, or responds so slowly as to be rendered essentially unavailable. Such attacks usually lead to a server overload. A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. Such an attack is often the result of multiple compromised systems (for example a botnet) flooding the targeted system with traffic. When a server is overloaded with connections, new connections can no longer be accepted. The major advantages to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine, and that the behavior of each attack machine can be stealthier, making it harder to track and shut down. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. This after all will end up completely crashing a website for periods of time. Malware can carry DDoS attack mechanisms; one of the better-known examples of this was MyDoom. Its DoS mechanism was triggered on a specific date and time. This type of DDoS involved hardcoding the target IP address prior to release of the malware and no further interaction was necessary to launch the attack.

CompTIA Security+ Question H-60

A distributed denial of service attack can BEST be described as:

A. Invalid characters being entered into a field in a database application.
B. Users attempting to input random or invalid data into fields within a web browser application.
C. Multiple computers attacking a single target in an organized attempt to deplete its resources.
D. Multiple attackers attempting to gain elevated privileges on a target system.

Answer: C

Explanation:
A Distributed Denial of Service (DDoS) attack is an attack from several different computers targeting a single computer. One common method of attack involves saturating the target machine with external communications requests, so much so that it cannot respond to legitimate traffic, or responds so slowly as to be rendered essentially unavailable. Such attacks usually lead to a server overload.

A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. Such an attack is often the result of multiple compromised systems (for example a botnet) flooding the targeted system with traffic. When a server is overloaded with connections, new connections can no longer be accepted. The major advantages to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine, and that the behavior of each attack machine can be stealthier, making it harder to track and shut down. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. This after all will end up completely crashing a website for periods of time. Malware can carry DDoS attack mechanisms; one of the better-known examples of this was MyDoom. Its DoS mechanism was triggered on a specific date and time. This type of DDoS involved hardcoding the target IP address prior to release of the malware and no further interaction was necessary to launch the attack.

CompTIA Security+ Question H-4

An administrator notices an unusual spike in network traffic from many sources. The administrator suspects that:

A. it is being caused by the presence of a rogue access point.
B. it is the beginning of a DDoS attack.
C. the IDS has been compromised.
D. the internal DNS tables have been poisoned.

Answer: B

Explanation:
A Distributed Denial of Service (DDoS) attack is an attack from several different computers targeting a single computer. One common method of attack involves saturating the target machine with external communications requests, so much so that it cannot respond to legitimate traffic, or responds so slowly as to be rendered essentially unavailable. Such attacks usually lead to a server overload.

A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. Such an attack is often the result of multiple compromised systems (for example a botnet) flooding the targeted system with traffic. When a server is overloaded with connections, new connections can no longer be accepted. The major advantages to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine, and that the behavior of each attack machine can be stealthier, making it harder to track and shut down. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. This after all will end up completely crashing a website for periods of time. Malware can carry DDoS attack mechanisms; one of the better-known examples of this was MyDoom. Its DoS mechanism was triggered on a specific date and time. This type of DDoS involved hardcoding the target IP address prior to release of the malware and no further interaction was necessary to launch the attack.

CompTIA Security+ Question E-52

Which of the following attacks impact the availability of a system? (Select TWO).

A. Smurf
B. Phishing
C. Spim
D. DDoS
E. Spoofing

Answer: A,D

Explanation:
A smurf attack is a type of network security breach in which a network connected to the Internet is swamped with replies to ICMP echo (PING) requests. A smurf attacker sends PING requests to an Internet broadcast address. These are special addresses that broadcast all received messages to the hosts connected to the subnet. Each broadcast address can support up to 255 hosts, so a single PING request can be multiplied 255 times. The return address of the request itself is spoofed to be the address of the attacker’s victim. All the hosts receiving the PING request reply to this victim’s address instead of the real sender’s address. A single attacker sending hundreds or thousands of these PING messages per second can fill the victim’s T-1 (or even T-3) line with ping replies, bring the entire Internet service to its knees. Smurfing falls under the general category of Denial of Service attacks — security attacks that don’t try to steal information, but instead attempt to disable a computer or network.

A Distributed Denial of Service (DDoS) attack is an attack from several different computers targeting a single computer. One common method of attack involves saturating the target machine with external communications requests, so much so that it cannot respond to legitimate traffic, or responds so slowly as to be rendered essentially unavailable. Such attacks usually lead to a server overload. A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. Such an attack is often the result of multiple compromised systems (for example a botnet) flooding the targeted system with traffic. When a server is overloaded with connections, new connections can no longer be accepted. The major advantages to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine, and that the behavior of each attack machine can be stealthier, making it harder to track and shut down. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. This after all will end up completely crashing a website for periods of time.

CompTIA Security+ Question B-11

Which of the following helps to establish an accurate timeline for a network intrusion?

A. Hashing images of compromised systems
B. Reviewing the date of the antivirus definition files
C. Analyzing network traffic and device logs
D. Enforcing DLP controls at the perimeter

Answer: C

Explanation:
Network activity as well as intrusion can be viewed on device logs and by analyzing the network traffic that passed through your network. Thus to establish an accurate timeline for a network intrusion you can look at and analyze the device logs and network traffic to yield the appropriate information.

CompTIA Network+ Question C-5

Packet analysis reveals multiple GET and POST requests from an internal host to a URL without any response from the server. Which of the following is the BEST explanation that describes this scenario?

A. Compromised system
B. Smurf attack
C. SQL injection attack
D. Man-in-the-middle

Correct Answer: A

Explanation:
As the extra unexplainable traffic comes from an internal host on your network we can assume that this host has been compromised.
If your system has been compromised, somebody is probably using your machine–possibly to scan and find other machines to compromise