Free Practice Questions for CompTIA CS0-003 Exam

Reconnaissance is the first stage in the Cyber Kill Chain and involves researching potential targets before carrying out any penetration testing. The reconnaissance stage may include identifying potential targets, finding their vulnerabilities, discovering which third parties are connected to them (and what data they can access), and exploring existing entry points as well as finding new ones. Reconnaissance can take place both online and offline. In this case, an analyst finds that an IP address outside of the company network is being used to run network and vulnerability scans across external-facing assets. This indicates that the analyst is witnessing reconnaissance activity by an attacker. Official References: https://www.lockheedmartin.com/en-us/capabilities/cyber/cyber-kill-chain.html

A mean time to remediate (MTTR) is a metric that measures how long it takes to fix a vulnerability after it is discovered. A MTTR of 30 days would best protect the organization from the new attacks that are exploited 45 days after a patch is released, as it would ensure that the vulnerabilities are fixed before they are exploited

USB ports are a common attack vector that can be used to deliver malware, steal data, or compromise systems. The first step to mitigate this vulnerability is to check the configurations of the company assets and disable or restrict the USB ports if possible. This will prevent unauthorized devices from being connected and reduce the attack surface. The other options are also important, but they are not the first priority in this scenario.

Registry key values would be missing from a scan performed with this configuration, as the scanner appliance would not have access to the Windows Registry of the scanned systems. The WindowsRegistry is a database that stores configuration settings and options for the operating system and installed applications. To scan the Registry, the scanner would need to have credentials to log in to the systems and run a local agent or script. The other items would not be missing from the scan, as they can be detected by the scanner appliance without credentials. Operating system version can be identified by analyzing service banners or fingerprinting techniques. Open ports can be discovered by performing a port scan or sending probes to common ports. IP address can be obtained by resolving the hostname or using network discovery tools. https://attack.mitre.org/techniques/T1112/

The correct answer is A. To ensure the report is legally acceptable in case it needs to be presented in court.

Proper handling and reporting of existing evidence are important for the investigation and reporting phases of an incident response because they ensure the integrity, authenticity, and admissibility of the evidence in case it needs to be presented in court. Evidence that is mishandled, tampered with, or poorly documented may not be accepted by the court or may be challenged by the opposing party. Therefore, incident responders should follow the best practices and standards for evidence collection, preservation, analysis, and reporting1.

The other options are not reasons why proper handling and reporting of existing evidence are important for the investigation and reporting phases of an incident response. They are rather outcomes or benefits of conducting a thorough and effective incident response process. A lessons-learned analysis (B) is a way to identify the strengths and weaknesses of the incident response team and improve their performance for future incidents. A postmortem analysis © is a way to determine the root cause, impact, and timeline of the incident and provide recommendations for remediation and prevention. A root cause analysis (D) is a way to identify the underlying factors that led to the incident and address them accordingly.

Indicators of compromise (IoCs) are pieces of data or evidence that suggest a system or network has been compromised by an attacker or malware. IoCs can include IP addresses, domain names, URLs, file hashes, registry keys, network traffic patterns, user behaviors, or system anomalies. IoCs can be used to detect, analyze, and respond to security incidents, as well as to share threat intelligence with other organizations or authorities. IoCs can produce the data needed for an executive briefing on possible threats to the organization, as they can provide information on the source, nature, scope, impact, and mitigation of the threats.

Placing a legal hold on the employee’s mailbox is the best action to perform first, as it preserves all mailbox content, including deleted items and original versions of modified items, for potential legal or forensic purposes. A legal hold is a feature that allows an administrator to retain mailbox data for a user indefinitely or for a specified period, regardless of the user’s actions or retention policies. A legal hold can be applied to a mailbox using Litigation Hold or In-Place Hold in Exchange Server or Exchange Online. A legal hold can help to ensure that evidence of data exfiltration or other malicious activities is not lost or tampered with, and that the organization can comply with any legal or regulatory obligations. The other actions are not as urgent or effective as placing a legal hold on the employee’s mailbox, as they do not address the immediate threat of data loss or compromise. Enabling filtering on the web proxy may help to prevent some types of data exfiltration or malicious traffic, but it does nothelp to recover or preserve the data that has already been emailed externally. Disabling the public email access with CASB (Cloud Access Security Broker) may help to block or monitor the use of public email services by employees, but it does not help to recover or preserve the data that has already been emailed externally. Configuring a deny rule on the firewall may help to block or monitor the network traffic from the employee’s laptop, but it does not help to recover or preserve the data that has already been emailed externally.

The correct regular expression to match a GET request to this API endpoint is "https://10\.1\.2\.3/api\?id=\d+". This pattern checks for the specific URL with an id parameter that accepts integer values. The syntax \d+ matches one or more digits, which aligns with the requirement for a single integer argument. Other options either use incorrect syntax or do not accurately capture the expected URL format. Regular expressions are vital in filtering and identifying patterns in logs, as recommended by CompTIA Cybersecurity Analyst (CySA+) practices for threat hunting and log analysis.

When prioritizing vulnerabilities, analysts consider theCVSS score, whether the system isinternet-facing, and ifsensitive datais involved. The primary goal is to mitigate the mostexploitableandimpactfulrisks first.

Let's break down the key components:

Attack Vector (AV): Whether the attack can be launched remotely (N = Network) or locally (L = Local).

Attack Complexity (AC): The difficulty of executing the attack (L = Low, H = High).

Privileges Required (PR): The level of access needed for exploitation (N = None, L = Low, H = High).

User Interaction (UI): Whether user interaction is required for the attack (N = No, R = Required).

Scope (S): Whether the attack affects other systems (C = Changed, U = Unchanged).

Confidentiality (C), Integrity (I), Availability (A): The impact level (H = High, L = Low, N = None).

Evaluating Each System:

System 1 (CVSS: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

Internet-facing✅

No sensitive data❌

High confidentiality and availability impact✅

Moderate risk due to requiring low privileges

System 2 (CVSS: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

Not internet-facing❌

No sensitive data❌

Lower priority since it’s local-only

System 3 (CVSS: AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L)

Internet-facing✅

Contains sensitive data✅

But very low likelihood of exploit (requires physical access, high privileges, user interaction)

Lower priority due to high attack complexity

System 4 (CVSS: AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:H)

Internet-facing✅

No sensitive data❌

No privileges required for exploitation✅

High impact on confidentiality and availability✅

Most critical due to remote exploitability and system-wide scope

System 5 (CVSS: AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N)

Internet-facing✅

Contains sensitive data✅

But requires high privileges, high attack complexity, and user interaction

Lower priority than System 4

System 6 (CVSS: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

Not internet-facing❌

No sensitive data❌

Same as System 2 (low priority due to being local-only)

Final Decision: Patch System 4 First

System 4 is themost criticalbecause:

It isinternet-facing(higher exposure).

It has ahigh CVSS score.

Itrequires no privileges(easy to exploit).

It hassystem-wide scope impact(can affect other systems).

Thus, it should bepatched firstto minimize security risks.

The function that would help the analyst identify IP addresses from the same country is:

function x() { info=$(geoiplookup $1) && echo “$1 | $info” }

This function takes an IP address as an argument and uses the geoiplookup command to get the geographic location information associated with the IP address, such as the country name, country code, region, city, or latitude and longitude. The function then prints the IP address and the geographic location information, which can help identify any IP addresses that belong to the same country.