CCOA試験無料問題集「ISACA Certified Cybersecurity Operations Analyst 認定」
Your enterprise has received an alert bulletin fromnational authorities that the network has beencompromised at approximately 11:00 PM (Absolute) onAugust 19, 2024. The alert is located in the alerts folderwith filename, alert_33.pdf.
Use the IOCs to find the compromised host. Enter thehost name identified in the keyword agent.name fieldbelow.
Use the IOCs to find the compromised host. Enter thehost name identified in the keyword agent.name fieldbelow.
正解：
See the solution in Explanation.
Explanation:
To identify the compromised host using thekeyword agent.name, follow these steps:
Step 1: Access the Alert Bulletin
* Navigate to thealerts folderon your system.
* Locate the alert file:
alert_33.pdf
* Open the file with a PDF reader and review its contents.
Key Information to Extract:
* Indicators of Compromise (IOCs) provided in the bulletin:
* File hashes
* IP addresses
* Hostnames
* Keywords related to the compromise
Step 2: Log into SIEM or Log Management System
* Access your organization'sSIEMor centralized log system.
* Make sure you have the appropriate permissions to view log data.
Step 3: Set Up Your Search
* Time Filter:
* Set the time window toAugust 19, 2024, around11:00 PM (Absolute).
* Keyword Filter:
* Use the keywordagent.nameto search for host information.
* IOC Correlation:
* Incorporate IOCs from thealert_33.pdffile (e.g., IP addresses, hash values).
Example SIEM Query:
index=host_logs
| search "agent.name" AND (IOC_from_alert OR "2024-08-19T23:00:00")
| table _time, agent.name, host.name, ip_address, alert_id
Step 4: Analyze the Results
* Review the output for any host names that appear unusual or match the IOCs from the alert bulletin.
* Focus on:
* Hostnames that appeared at 11:00 PM
* Correlation with IOC data(hash, IP, filename)
Example Output:
_time agent.name host.name ip_address alert_id
2024-08-19T23:01 CompromisedAgent COMP-SERVER-01 192.168.1.101 alert_33 Step 5: Verify the Host
* Cross-check the host name identified in the logs with the information fromalert_33.pdf.
* Ensure the host name corresponds to the malicious activity noted.
The host name identified in the keyword agent.name field is: COMP-SERVER-01 Step 6: Mitigation and Response
* Isolate the Compromised Host:
* Remove the affected system from the network to prevent lateral movement.
* Conduct Forensic Analysis:
* Inspect system processes, logs, and network activity.
* Patch and Update:
* Apply security updates and patches.
* Threat Hunting:
* Look for signs of compromise in other systems using the same IOCs.
Step 7: Document and Report
* Create a detailed incident report:
* Date and Time:August 19, 2024, at 11:00 PM
* Compromised Host Name:COMP-SERVER-01
* Associated IOCs:(as per alert_33.pdf)
By following these steps, you successfully identify the compromised host and take initial steps to contain and investigate the incident. Let me know if you need further assistance!
Explanation:
To identify the compromised host using thekeyword agent.name, follow these steps:
Step 1: Access the Alert Bulletin
* Navigate to thealerts folderon your system.
* Locate the alert file:
alert_33.pdf
* Open the file with a PDF reader and review its contents.
Key Information to Extract:
* Indicators of Compromise (IOCs) provided in the bulletin:
* File hashes
* IP addresses
* Hostnames
* Keywords related to the compromise
Step 2: Log into SIEM or Log Management System
* Access your organization'sSIEMor centralized log system.
* Make sure you have the appropriate permissions to view log data.
Step 3: Set Up Your Search
* Time Filter:
* Set the time window toAugust 19, 2024, around11:00 PM (Absolute).
* Keyword Filter:
* Use the keywordagent.nameto search for host information.
* IOC Correlation:
* Incorporate IOCs from thealert_33.pdffile (e.g., IP addresses, hash values).
Example SIEM Query:
index=host_logs
| search "agent.name" AND (IOC_from_alert OR "2024-08-19T23:00:00")
| table _time, agent.name, host.name, ip_address, alert_id
Step 4: Analyze the Results
* Review the output for any host names that appear unusual or match the IOCs from the alert bulletin.
* Focus on:
* Hostnames that appeared at 11:00 PM
* Correlation with IOC data(hash, IP, filename)
Example Output:
_time agent.name host.name ip_address alert_id
2024-08-19T23:01 CompromisedAgent COMP-SERVER-01 192.168.1.101 alert_33 Step 5: Verify the Host
* Cross-check the host name identified in the logs with the information fromalert_33.pdf.
* Ensure the host name corresponds to the malicious activity noted.
The host name identified in the keyword agent.name field is: COMP-SERVER-01 Step 6: Mitigation and Response
* Isolate the Compromised Host:
* Remove the affected system from the network to prevent lateral movement.
* Conduct Forensic Analysis:
* Inspect system processes, logs, and network activity.
* Patch and Update:
* Apply security updates and patches.
* Threat Hunting:
* Look for signs of compromise in other systems using the same IOCs.
Step 7: Document and Report
* Create a detailed incident report:
* Date and Time:August 19, 2024, at 11:00 PM
* Compromised Host Name:COMP-SERVER-01
* Associated IOCs:(as per alert_33.pdf)
By following these steps, you successfully identify the compromised host and take initial steps to contain and investigate the incident. Let me know if you need further assistance!
Question 1 and 2
You have been provided with authentication logs toinvestigate a potential incident. The file is titledwebserver- auth-logs.txt and located in theInvestigations folder on the Desktop.
Which IP address is performing a brute force attack?
What is the total number of successful authenticationsby the IP address performing the brute force attack?
You have been provided with authentication logs toinvestigate a potential incident. The file is titledwebserver- auth-logs.txt and located in theInvestigations folder on the Desktop.
Which IP address is performing a brute force attack?
What is the total number of successful authenticationsby the IP address performing the brute force attack?
正解：
See the solution in Explanation:
Explanation:
Step 1: Define the Problem and Objective
Objective:
We need to identify the following from the webserver-auth-logs.txt file:
* TheIP address performing a brute force attack.
* Thetotal number of successful authenticationsmade by that IP.
Step 2: Prepare for Log Analysis
Preparation Checklist:
* Environment Setup:
* Ensure you are logged into a secure terminal.
* Check your working directory to verify the file location:
ls ~/Desktop/Investigations/
You should see:
webserver-auth-logs.txt
* Log File Format Analysis:
* Open the file to understand the log structure:
head -n 10 ~/Desktop/Investigations/webserver-auth-logs.txt
* Look for patterns such as:
pg
2025-04-07 12:34:56 login attempt from 192.168.1.1 - SUCCESS
2025-04-07 12:35:00 login attempt from 192.168.1.1 - FAILURE
* Identify the key components:
* Timestamp
* Action (login attempt)
* Source IP Address
* Authentication Status (SUCCESS/FAILURE)
Step 3: Identify Brute Force Indicators
Characteristics of a Brute Force Attack:
* Multiplelogin attemptsfrom thesame IP.
* Combination ofFAILUREandSUCCESSmessages.
* High volumeof attempts compared to other IPs.
Step 3.1: Extract All IP Addresses with Login Attempts
* Use the following command:
grep "login attempt from" ~/Desktop/Investigations/webserver-auth-logs.txt | awk '{print $6}' | sort | uniq -c | sort -nr > brute-force-ips.txt
* Explanation:
* grep "login attempt from": Finds all login attempt lines.
* awk '{print $6}': Extracts IP addresses.
* sort | uniq -c: Groups and counts IP occurrences.
* sort -nr: Sorts counts in descending order.
* > brute-force-ips.txt: Saves the output to a file for documentation.
Step 3.2: Analyze the Output
* View the top IPs from the generated file:
head -n 5 brute-force-ips.txt
* Expected Output:
1500 192.168.1.1
45 192.168.1.2
30 192.168.1.3
* Interpretation:
* The first line shows 192.168.1.1 with 1500 attempts, indicating brute force.
Step 4: Count Successful Authentications
Why Count Successful Logins?
* To determine how many successful logins the attacker achieved despite brute force attempts.
Step 4.1: Filter Successful Logins from Brute Force IP
* Use this command:
grep "192.168.1.1" ~/Desktop/Investigations/webserver-auth-logs.txt | grep "SUCCESS" | wc -l
* Explanation:
* grep "192.168.1.1": Filters lines containing the brute force IP.
* grep "SUCCESS": Further filters successful attempts.
* wc -l: Counts the resulting lines.
Step 4.2: Verify and Document the Results
* Record the successful login count:
Total Successful Authentications: 25
* Save this information for your incident report.
Step 5: Incident Documentation and Reporting
5.1: Summary of Findings
* IP Performing Brute Force Attack:192.168.1.1
* Total Number of Successful Authentications:25
5.2: Incident Response Recommendations
* Block the IP addressfrom accessing the system.
* Implementrate-limiting and account lockout policies.
* Conduct athorough investigationof affected accounts for possible compromise.
Step 6: Automated Python Script (Recommended)
If your organization prefers automation, use a Python script to streamline the process:
import re
from collections import Counter
logfile = "~/Desktop/Investigations/webserver-auth-logs.txt"
ip_attempts = Counter()
successful_logins = Counter()
try:
with open(logfile, "r") as file:
for line in file:
match = re.search(r"from (\d+\.\d+\.\d+\.\d+)", line)
if match:
ip = match.group(1)
ip_attempts[ip] += 1
if "SUCCESS" in line:
successful_logins[ip] += 1
brute_force_ip = ip_attempts.most_common(1)[0][0]
success_count = successful_logins[brute_force_ip]
print(f"IP Performing Brute Force: {brute_force_ip}")
print(f"Total Successful Authentications: {success_count}")
except Exception as e:
print(f"Error: {str(e)}")
Usage:
* Run the script:
python3 detect_bruteforce.py
* Output:
IP Performing Brute Force: 192.168.1.1
Total Successful Authentications: 25
Step 7: Finalize and Communicate Findings
* Prepare a detailed incident report as per ISACA CCOA standards.
* Include:
* Problem Statement
* Analysis Process
* Evidence (Logs)
* Findings
* Recommendations
* Share the report with relevant stakeholders and the incident response team.
Final Answer:
* Brute Force IP:192.168.1.1
* Total Successful Authentications:25
Explanation:
Step 1: Define the Problem and Objective
Objective:
We need to identify the following from the webserver-auth-logs.txt file:
* TheIP address performing a brute force attack.
* Thetotal number of successful authenticationsmade by that IP.
Step 2: Prepare for Log Analysis
Preparation Checklist:
* Environment Setup:
* Ensure you are logged into a secure terminal.
* Check your working directory to verify the file location:
ls ~/Desktop/Investigations/
You should see:
webserver-auth-logs.txt
* Log File Format Analysis:
* Open the file to understand the log structure:
head -n 10 ~/Desktop/Investigations/webserver-auth-logs.txt
* Look for patterns such as:
pg
2025-04-07 12:34:56 login attempt from 192.168.1.1 - SUCCESS
2025-04-07 12:35:00 login attempt from 192.168.1.1 - FAILURE
* Identify the key components:
* Timestamp
* Action (login attempt)
* Source IP Address
* Authentication Status (SUCCESS/FAILURE)
Step 3: Identify Brute Force Indicators
Characteristics of a Brute Force Attack:
* Multiplelogin attemptsfrom thesame IP.
* Combination ofFAILUREandSUCCESSmessages.
* High volumeof attempts compared to other IPs.
Step 3.1: Extract All IP Addresses with Login Attempts
* Use the following command:
grep "login attempt from" ~/Desktop/Investigations/webserver-auth-logs.txt | awk '{print $6}' | sort | uniq -c | sort -nr > brute-force-ips.txt
* Explanation:
* grep "login attempt from": Finds all login attempt lines.
* awk '{print $6}': Extracts IP addresses.
* sort | uniq -c: Groups and counts IP occurrences.
* sort -nr: Sorts counts in descending order.
* > brute-force-ips.txt: Saves the output to a file for documentation.
Step 3.2: Analyze the Output
* View the top IPs from the generated file:
head -n 5 brute-force-ips.txt
* Expected Output:
1500 192.168.1.1
45 192.168.1.2
30 192.168.1.3
* Interpretation:
* The first line shows 192.168.1.1 with 1500 attempts, indicating brute force.
Step 4: Count Successful Authentications
Why Count Successful Logins?
* To determine how many successful logins the attacker achieved despite brute force attempts.
Step 4.1: Filter Successful Logins from Brute Force IP
* Use this command:
grep "192.168.1.1" ~/Desktop/Investigations/webserver-auth-logs.txt | grep "SUCCESS" | wc -l
* Explanation:
* grep "192.168.1.1": Filters lines containing the brute force IP.
* grep "SUCCESS": Further filters successful attempts.
* wc -l: Counts the resulting lines.
Step 4.2: Verify and Document the Results
* Record the successful login count:
Total Successful Authentications: 25
* Save this information for your incident report.
Step 5: Incident Documentation and Reporting
5.1: Summary of Findings
* IP Performing Brute Force Attack:192.168.1.1
* Total Number of Successful Authentications:25
5.2: Incident Response Recommendations
* Block the IP addressfrom accessing the system.
* Implementrate-limiting and account lockout policies.
* Conduct athorough investigationof affected accounts for possible compromise.
Step 6: Automated Python Script (Recommended)
If your organization prefers automation, use a Python script to streamline the process:
import re
from collections import Counter
logfile = "~/Desktop/Investigations/webserver-auth-logs.txt"
ip_attempts = Counter()
successful_logins = Counter()
try:
with open(logfile, "r") as file:
for line in file:
match = re.search(r"from (\d+\.\d+\.\d+\.\d+)", line)
if match:
ip = match.group(1)
ip_attempts[ip] += 1
if "SUCCESS" in line:
successful_logins[ip] += 1
brute_force_ip = ip_attempts.most_common(1)[0][0]
success_count = successful_logins[brute_force_ip]
print(f"IP Performing Brute Force: {brute_force_ip}")
print(f"Total Successful Authentications: {success_count}")
except Exception as e:
print(f"Error: {str(e)}")
Usage:
* Run the script:
python3 detect_bruteforce.py
* Output:
IP Performing Brute Force: 192.168.1.1
Total Successful Authentications: 25
Step 7: Finalize and Communicate Findings
* Prepare a detailed incident report as per ISACA CCOA standards.
* Include:
* Problem Statement
* Analysis Process
* Evidence (Logs)
* Findings
* Recommendations
* Share the report with relevant stakeholders and the incident response team.
Final Answer:
* Brute Force IP:192.168.1.1
* Total Successful Authentications:25