Exam CAS-004 topic 1 question 390 discussion

The regex expression is a exact match!

The best solutions to implement to stop this specific attack are: A. Intrusion prevention system: An IPS can be configured to detect and block suspicious patterns of data, such as the specific exfiltration pattern identified here. D. reject icmp any any <> any any (msg:"alert"; regex [a-z]{26}[0-9]{5}): This rule uses a regular expression to match the pattern of 26 lowercase letters followed by 5 digits, which can be used to detect and reject packets containing the suspected encoded sensitive information.

DLP tools are not (generally) designed to detect ICMP based data exfiltration.

The best solutions are A. Intrusion prevention system and B. Data loss prevention, as these technologies can detect and prevent the data exfiltration attack by identifying and blocking the sensitive data transfer based on the described pattern.

A. Intrusion prevention system (IPS) An IPS can monitor network traffic for suspicious patterns and malicious activity. By implementing the correct rules, it can detect and block attempts to exfiltrate data based on the pattern described (e.g., the last five digits encoding sensitive information). The IPS could potentially block the malicious traffic or alert the analyst when it matches a known pattern of data exfiltration. B. Data loss prevention (DLP) Data Loss Prevention (DLP) solutions are specifically designed to prevent the unauthorized transfer of sensitive data. In this case, DLP can be configured to look for specific patterns in the data, such as the last five digits in the payload encoding sensitive information, and prevent this data from being exfiltrated over the network.

A. Intrusion Prevention System (IPS) Implement an IPS with a custom rule to detect and block the specific pattern in the data payload. The rule could use a regex pattern to match the last five digits. D. reject icmp any any <> any any (msg:"alert"; regex [a-z]{26}[0-9]{5}) This Snort rule (or a similar rule in another IPS) can detect ICMP packets with a specific pattern where 26 alphabetic characters are followed by 5 numeric digits. This rule will help in identifying and blocking the suspicious data exfiltration pattern. Justification:

AD: D - A SNORT rule rejecting from any ip/port to any ip/port, either outbound or inbound ('<>') matching the RegEx. A - SNORT rules are not applied on a DLP, they are applied to NIPS.

Maybe I'm overthinking this, but a Combo of A and B works well in this scenario: A) Configure DLP to identify and block the encoded data with the five-digit pattern from being transferred, regardless of protocol. B) Create an IPS rule to identify and block ICMP packets with a payload of 31 bytes (26 alpha and five numeric patterns) from the internal network.

B. Data loss prevention Brief Explanation: DLP systems can be configured to recognize and prevent the transfer of sensitive information based on patterns, like the last five digits in this scenario. D. Reject icmp any any <> any (msg:"alert"; regex: [a-z]{26}[0-9]{5}) Brief Explanation: This rule is written for a network-based intrusion prevention system (IPS). It uses a regular expression to match the pattern of 26 letters followed by 5 digits, which corresponds to the suspected data exfiltration pattern.

A & D because it requires a technology along with a rule to be applied while using it. THe only rule I see is the one for an IPS. DLP would be good, but I don't see a rule that can be applied along with option B

D is Snort rule with a regex expression that will prevent this attack While B is a viable answer, A is a better answer since it compliments D (Snort is an IPS)

It's B and D: B is obvious and I think everyone can agree that a DLP would be ideal in such scenarios. The only dilemma is between A (IPS) and D, which is a very accurate Regex pattern that rejects any ICMP traffic between any sources and destinations that contain a specific pattern: 26 consecutive lowercase letters followed by 5 consecutive digits. This pattern already implies that there is an IPS in place, so it's more accurate than selecting A.

To mitigate the data exfiltration attack, the analyst could implement Data Loss Prevention (DLP) technology with rules specifically targeting patterns involving the last five digits, preventing sensitive information from being encoded or leaked.

B. Data loss prevention (DLP): DLP solutions are designed to identify, monitor, and protect sensitive data to prevent unauthorized access or transmission. By implementing DLP policies that specifically target and inspect traffic for patterns resembling the suspected data exfiltration (e.g., identifying the sensitive information format in the last five digits), the DLP system can block or alert on such transmissions. D. Intrusion prevention system (IPS): IPS solutions can be configured with rules and signatures to detect and prevent suspicious or malicious network activity. A custom signature or rule can be created within the IPS that specifically looks for the suspected pattern observed in the data portion of the captured packets. For instance, a signature similar to the provided regex pattern [a-z]{26}[0-9]{5} might be employed within the IPS to detect this specific data exfiltration attempt.

Answer is AB since D does not exactly match what is being exfiltrated. If D was correct then it should be AD based on the context of the question asking for a specific rule