CompTIA CS0-002 Exam

Modbus is a communication protocol that is widely used in industrial control systems (ICS) and supervisory control and data acquisition (SCADA) systems. However, Modbus was not designed to provide security and it is vulnerable to various cyberattacks. One of the main vulnerabilities of Modbus is the lack of authentication, which means that any device on the network can send or receive commands without verifying its identity or authority. This can lead to unauthorized access, data manipulation, or denial of service attacks on the ICS or SCADA system.

Some examples of attacks that exploit the lack of authentication in Modbus are:

Detection attack: An attacker can scan the network and discover the devices and their addresses, functions, and registers by sending Modbus requests and observing the responses.This can reveal sensitive information about the system configuration and operation1.

Command injection attack: An attacker can send malicious commands to the devices and modify their settings, values, or outputs.For example, an attacker can change the speed of a motor, open or close a valve, or turn off a switch23.

Response injection attack: An attacker can intercept and alter the responses from the devices and deceive the master or other devices about the true state of the system.For example, an attacker can fake a normal response when there is an error or an alarm23.

Denial of service attack: An attacker can flood the network with Modbus requests or commands and overload the devices or the communication channel.This can prevent legitimate requests or commands from being processed and disrupt the normal operation of the system14.

To mitigate these attacks, some security measures that can be applied to Modbus are:

Encryption: Encrypting the Modbus messages can prevent eavesdropping and tampering by unauthorized parties.However, encryption can also introduce additional overhead and latency to the communication56.

Authentication: Adding authentication mechanisms to Modbus can ensure that only authorized devices can send or receive commands.Authentication can be based on passwords, certificates, tokens, or other methods56.

Firewall: Installing a firewall between the Modbus network and other networks can filter out unwanted traffic and block unauthorized access.A firewall can also enforce rules and policies for Modbus communication24.

Intrusion detection system: Deploying an intrusion detection system (IDS) on the Modbus network can monitor the traffic and detect anomalous or malicious activities.An IDS can also alert the operators or trigger countermeasures when an attack is detected24.

PII stands for personally identifiable information, and it is any data that can be used to identify, contact, or locate a specific individual, such as name, address, phone number, email, social security number, or biometric data. PII data is considered critical because it can be used by attackers to commit identity theft, fraud, or other crimes.PII data is also subject to various laws and regulations that require organizations to protect it from unauthorized access, use, or disclosure1.

The objective of a BIA is to determine the potential impacts of various disruptions on the business processes and functions, and to establish the recovery priorities and objectives for each process and function. To achieve this objective, the analyst needs to consider various measures and metrics that can quantify the impacts and the recovery requirements. Some of the common measures and metrics that are used in a BIA are:

Maximum downtime before impact is unacceptable: This metric defines the maximum amount of time that a business process or function can be disrupted without causing significant or irreversible damage to the organization's reputation, operations, finances, or legal obligations. This metric is also known as the maximum tolerable downtime (MTD) or maximum tolerable period of disruption (MTPD).It helps to determine the recovery time objective (RTO), which is the target time for restoring the process or function to an acceptable level of service after a disruption1.

Total time accepted for business process outage: This metric defines the total amount of time that a business process or function can be out of service within a given period, such as a day, a week, or a month.This metric is also known as the recovery point objective (RPO), which is the maximum amount of data loss or corruption that can be tolerated after a disruption1. It helps to determine the backup frequency and retention policy for the data and systems that support the process or function.

Time required to inform stakeholders about outage: This metric defines the time frame for communicating with the internal and external stakeholders who are affected by or involved in the disruption and recovery of a business process or function.This metric helps to establish the crisis communication plan and protocol, which specifies who, what, when, where, why, and how to communicate during and after a disruption2. It also helps to manage the expectations and perceptions of the stakeholders and to maintain their trust and confidence in the organization.

Time to reimage the server: This metric defines the time needed to restore a server to its original or desired state after a disruption. This metric helps to estimate the resources and efforts required for recovering the server and its applications.It also helps to evaluate the feasibility and effectiveness of different recovery strategies, such as restoring from backup, rebuilding from scratch, or replacing with a spare3.

Minimum data backup volume: This metric defines the minimum amount of data that needs to be backed up regularly to ensure the continuity and integrity of a business process or function. This metric helps to optimize the backup process and reduce the storage costs and bandwidth consumption.It also helps to identify the critical data elements and sources that are essential for the process or function4.

The correct answer is D. Honeypot. A honeypot is a security mechanism designed to detect and deflect attempts at unauthorized use of information systems. In this case, the analyst has set up a system to listen on a network port that is commonly used for email traffic. The purpose of this honeypot is to attract attackers and allow the security analyst to observe their behavior and tactics.By monitoring the traffic that is captured in the caplog.txt file, the analyst can identify attacks that were not blocked by the organization's firewalls1.

The correct answer is B. The analyst should block requests to no-thanks.invalid. The log snippet shows a DNS query from host 192.168.1.67 to the public resolver 8.8.8.8 for the domain name no-thanks.invalid, which is resolved to the IP address 102.100.20.20.This is a possible indicator of compromise (IOC), as no-thanks.invalid is a known malicious domain that is used by attackers to exfiltrate data or execute commands on compromised hosts1. The analyst should block requests to this domain to prevent further communication with the attacker's server and investigate the host 192.168.1.67 for signs of infection.