Isaca Updated CCOA Exam Questions and Answers by harper

To identify thefile namethat triggered theRuleName: Suspicious PowerShellon theaccounting-pcworkstation, follow these detailed steps:

Step 1: Access the SIEM System

Open your web browser and navigate to theSIEM dashboard.

Log in with youradministrator credentials.

Step 2: Set Up the Query

Go to theSearchorQuerysection of the SIEM.

Set theTime Rangeto thelast 24 hours.

Query Parameters:

Agent Name:accounting-pc

Rule Name:Suspicious PowerShell

Event Type:Startup items or Process creation

Step 3: Construct the SIEM Query

Here’s an example of how to construct the query:

Example Query (Splunk):

index=windows_logs

| search agent.name="accounting-pc" RuleName="Suspicious PowerShell"

| where _time > now() - 24h

| table _time, agent.name, process_name, file_path, RuleName

Example Query (Elastic SIEM):

{

"query": {

"bool": {

"must": [

{ "match": { "agent.name": "accounting-pc" }},

{ "match": { "RuleName": "Suspicious PowerShell" }},

{ "range": { "@timestamp": { "gte": "now-24h" }}}

]

}

}

}

Step 4: Analyze the Query Results

The query should return a table or list containing:

Time of Execution

Agent Name:accounting-pc

Process Name

File Path

Rule Name

Example Output:

_time

agent.name

process_name

file_path

RuleName

2024-04-07T10:45:23

accounting-pc

powershell.exe

C:\Users\Accounting\AppData\Roaming\calc.ps1

Suspicious PowerShell

Step 5: Identify the Suspicious File

Theprocess_namein the output showspowershell.exeexecuting a suspicious script.

Thefile pathindicates the script responsible:

makefile

C:\Users\Accounting\AppData\Roaming\calc.ps1

The suspicious script file is:

calc.ps1

Step 6: Confirm the Malicious Nature

Manual Inspection:

Navigate to the specified file path on theaccounting-pcworkstation.

Check the contents of calc.ps1 for any malicious PowerShell code.

Hash Verification:

Generate theSHA256 hashof the file and compare it with known malware signatures.

Answer:

calc.ps1

Step 7: Immediate Response

Isolate the Workstation:Disconnectaccounting-pcfrom the network.

Terminate the Malicious Process:

Stop the powershell.exe process running calc.ps1.

Use Task Manager or a script:

powershell

Stop-Process -Name "powershell" -Force

Remove the Malicious Script:

powershell

Remove-Item "C:\Users\Accounting\AppData\Roaming\calc.ps1" -Force

Scan for Persistence Mechanisms:

CheckStartup itemsandScheduled Tasksfor any references to calc.ps1.

Step 8: Documentation

Record the following:

Date and Time:When the incident was detected.

Affected Host:accounting-pc

Malicious File:calc.ps1

Actions Taken:File removal and process termination.

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

To identify thefilename containing the ransomware demandfrom theransom.pcapfile, follow these detailed steps:

Step 1: Access the PCAP File

Log into the Analyst Desktop.

Navigate to theInvestigationsfolder located on the desktop.

Locate the file:

ransom.pcap

Step 2: Open the PCAP File in Wireshark

LaunchWireshark.

Open the PCAP file:

mathematica

File > Open > Desktop > Investigations > ransom.pcap

ClickOpento load the file.

Step 3: Apply Relevant Filters

Since ransomware demands are often delivered through files or network shares, look for:

Common Protocols:

SMB(for network shares)

HTTP/HTTPS(for download or communication)

Apply a general filter to capture suspicious file transfers:

kotlin

http or smb or ftp-data

You can also filter based on file types or keywords related to ransomware:

frame contains "README" or frame contains "ransom"

Step 4: Identify Potential Ransomware Files

Look for suspicious file transfers:

CheckHTTP GET/POSTorSMB file writeoperations.

Analyze File Names:

Ransom notes commonly use filenames such as:

README.txt

DECRYPT_INSTRUCTIONS.html

HELP_DECRYPT.txt

Right-click on any suspicious packet and select:

arduino

Follow > TCP Stream

Inspect the content to see if it contains a ransom note or instructions.

Step 5: Extract the File

If you find a packet with afile transfer, extract it:

mathematica

File > Export Objects > HTTP or SMB

Save the suspicious file to analyze its contents.

Step 6: Example Packet Details

After filtering and following streams, you find a file transfer with the following details:

makefile

GET /uploads/README.txt HTTP/1.1

Host: 10.10.44.200

User-Agent: Mozilla/5.0

After exporting, open the file and examine the content:

pg

Your files have been encrypted!

To recover them, you must pay in Bitcoin.

Read this file carefully for payment instructions.

Answer:

README.txt

Step 7: Confirm and Document

File Name:README.txt

Transmission Protocol:HTTP or SMB

Content:Contains ransomware demand and payment instructions.

Step 8: Immediate Actions

Isolate Infected Systems:

Disconnect compromised hosts from the network.

Preserve the PCAP and Extracted File:

Store them securely for forensic analysis.

Analyze the Ransomware Note:

Look for:

Bitcoin addresses

Contact instructions

Identifiers for ransomware family

Step 9: Report the Incident

Include the following details:

Filename:README.txt

Method of Delivery:HTTP (or SMB)

Ransomware Message:Payment in Bitcoin

Submit the report to your incident response team for further action.

Step 1: Understand the Objective

Objective:

Identify thedomain name(s)that werecontactedbetween:

12:10 AM to 12:12 AM on August 17, 2024

Source of information:

CCOA Threat Bulletin.pdf

File location:

~/Desktop/CCOA Threat Bulletin.pdf

Step 2: Prepare for Investigation

2.1: Ensure Access to the File

Check if the PDF exists:

ls ~/Desktop | grep "CCOA Threat Bulletin.pdf"

Open the file to inspect:

xdg-open ~/Desktop/CCOA\ Threat\ Bulletin.pdf

Alternatively, convert to plain text for easier analysis:

pdftotext ~/Desktop/CCOA\ Threat\ Bulletin.pdf ~/Desktop/threat_bulletin.txt

cat ~/Desktop/threat_bulletin.txt

2.2: Analyze the Content

Look for domain names listed in the bulletin.

Make note ofany domainsorURLsmentioned as IoCs (Indicators of Compromise).

Example:

suspicious-domain.com

malicious-actor.net

threat-site.xyz

Step 3: Locate Network Logs

3.1: Find the Logs Directory

The logs could be located in one of the following directories:

/var/log/

/home/administrator/hids/logs/

/var/log/httpd/

/var/log/nginx/

Navigate to the likely directory:

cd /var/log/

ls -l

Identify relevant network or DNS logs:

ls -l | grep -E "dns|network|http|nginx"

Step 4: Search Logs for Domain Contacts

4.1: Use the Grep Command to Filter Relevant Timeframe

Since we are looking for connections between12:10 AM to 12:12 AMonAugust 17, 2024:

grep "2024-08-17 00:1[0-2]" /var/log/dns.log

Explanation:

grep "2024-08-17 00:1[0-2]": Matches timestamps between00:10and00:12.

Replace dns.log with the actual log file name, if different.

4.2: Further Filter for Domain Names

To specifically filter out the domains listed in the bulletin:

grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)" /var/log/dns.log

If the logs are in another file, adjust the file path:

grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)" /var/log/nginx/access.log

Step 5: Correlate Domains and Timeframe

5.1: Extract and Format Relevant Results

Combine the commands to get time-specific domain hits:

grep "2024-08-17 00:1[0-2]" /var/log/dns.log | grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)"

Sample Output:

2024-08-17 00:11:32 suspicious-domain.com accessed by 192.168.1.50

2024-08-17 00:12:01 malicious-actor.net accessed by 192.168.1.75

Interpretation:

The command revealswhich domain(s)were contacted during the specified time.

Step 6: Verification and Documentation

6.1: Verify Domain Matches

Cross-check the domains in the log output against those listed in theCCOA Threat Bulletin.pdf.

Ensure that the time matches the specified range.

6.2: Save the Results for Reporting

Save the output to a file:

grep "2024-08-17 00:1[0-2]" /var/log/dns.log | grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)" > ~/Desktop/domain_hits.txt

Review the saved file:

cat ~/Desktop/domain_hits.txt

Step 7: Report the Findings

Final Answer:

Domain(s) Contacted:

suspicious-domain.com

malicious-actor.net

Time of Contact:

Between 12:10 AM to 12:12 AM on August 17, 2024

Reasoning:

Matched thelog timestampsanddomain nameswith the threat bulletin.

Step 8: Recommendations:

Immediate Block:

Add the identified domains to theblockliston firewalls and intrusion detection systems.

Monitor for Further Activity:

Keep monitoring logs for any further connection attempts to the same domains.

Perform IOC Scanning:

Check hosts that communicated with these domains for possible compromise.

Incident Report:

Document the findings and mitigation actions in theincident response log.