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