Free Isaca CCOA Practice Exam with Questions & Answers | Set: 2

Amesh network topologyis the most resilient to network failures because:

Redundancy:Each node is interconnected, providing multiple pathways for data to travel.

No Single Point of Failure:If one connection fails, data can still be routed through alternative paths.

High Fault Tolerance:The decentralized structure ensures that the failure of a single device or link does not significantly impact network performance.

Ideal for Critical Infrastructure:Often used in environments where uptime is critical, such as financial or emergency services networks.

Other options analysis:

B. Star:A central hub connects all nodes, so if the hub fails, the entire network collapses.

C. Bus:A single backbone cable means a break in the cable can disrupt the entire network.

D. Ring:Data travels in a circular path; a single break can isolate part of the network unless it is a dual-ring topology.

CCOA Official Review Manual, 1st Edition References:

Chapter 4: Network Security Operations:Discusses network topology and its impact on reliability and redundancy.

Chapter 9: Network Design and Architecture:Highlights resilient topologies, including mesh, for secure and fault-tolerant operations.

To identify thefull User-Agent valueassociated with theransomware demand file downloadfrom 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: Filter HTTP Traffic

Since ransomware demands are often served astext files (e.g., README.txt)via HTTP/S, use the following filter:

http.request or http.response

This filter will show bothHTTP GETandPOSTrequests.

Step 4: Locate the Ransomware Demand File Download

Look for HTTPGETrequests that include common ransomware filenames such as:

README.txt

DECRYPT_INSTRUCTIONS.html

HELP_DECRYPT.txt

Right-click on the suspicious HTTP packet and select:

arduino

Follow > HTTP Stream

Analyze theHTTP headersto find theUser-Agent.

Example HTTP Request:

GET /uploads/README.txt HTTP/1.1

Host: 10.10.44.200

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.75 Safari/537.36

Step 5: Verify the User-Agent

Check multiple streams to ensure consistency.

Confirm that theUser-Agentbelongs to the same host(10.10.44.200)involved in the ransomware incident.

Answer:

swift

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.75 Safari/537.36

Step 6: Document and Report

Record the User-Agent for analysis:

PCAP Filename:ransom.pcap

User-Agent:Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.75 Safari/537.36

Related File:README.txt

Step 7: Next Steps

Forensic Analysis:

Look for more HTTP requests from the sameUser-Agent.

Monitor Network Activity:

Identify other systems with the same User-Agent pattern.

Block Malicious Traffic:

Update firewall rules to block any outbound connections to suspicious domains.

To identify thename of the servicethat the malware attempts to install from theMalscript.viruz.txtfile, follow these steps:

Step 1: Access the Analyst Desktop

Log into the Analyst Desktopusing your credentials.

Navigate to theMalware Samplesfolder located on the desktop.

Locate the file:

Malscript.viruz.txt

Step 2: Examine the File Contents

Open the file with a text editor:

Windows:Right-click > Open with > Notepad.

Linux:

cat ~/Desktop/Malware\ Samples/malscript.viruz.txt

Review the content to identify any lines that relate to:

Service creation

Service names

Installation commands

Common Keywords to Look For:

New-Service

sc create

Install-Service

Set-Service

net start

Step 3: Identify the Service Creation Command

Malware typically uses commands like:

powershell

New-Service -Name "MalService" -BinaryPathName "C:\Windows\malicious.exe"

or

cmd

sc create MalService binPath= "C:\Windows\System32\malicious.exe"

Focus on lines where the malware tries toregister or create a service.

Step 4: Example Content from Malscript.viruz.txt

arduino

powershell.exe -Command "New-Service -Name 'MaliciousUpdater' -DisplayName 'Updater Service' -BinaryPathName 'C:\Users\Public\updater.exe' -StartupType Automatic"

In this example, thename of the serviceis:

nginx

MaliciousUpdater

Step 5: Cross-Verification

Check for multiple occurrences of service creation in the script to ensure accuracy.

Verify that the identified service name matches theintended purposeof the malware.

Answer:

pg

The name of the service that the malware attempts to install is: MaliciousUpdater

Step 6: Immediate Action

Check for the Service:

powershell

Get-Service -Name "MaliciousUpdater"

Stop and Remove the Service:

powershell

Stop-Service -Name "MaliciousUpdater" -Force

sc delete "MaliciousUpdater"

Remove Associated Executable:

powershell

Remove-Item "C:\Users\Public\updater.exe" -Force

Step 7: Documentation

Record the following:

Service Name:MaliciousUpdater

Installation Command:Extracted from Malscript.viruz.txt

File Path:C:\Users\Public\updater.exe

Actions Taken:Stopped and deleted the service.

To determine the host IP of the machine vulnerable toCVE-2021-22145usingGreenbone Vulnerability Manager (GVM), follow these detailed steps:

Step 1: Access Greenbone Vulnerability Manager

OpenFirefoxon your system.

Go to the GVM login page:

URL: https://10.10.55.4:9392

Enter the credentials:

Username: admin

Password: Secure-gvm!

ClickLoginto access the dashboard.

Step 2: Navigate to Scan Reports

Once logged in, locate the"Scans"menu on the left panel.

Click on"Reports"under the"Scans"section to view the list of completed vulnerability scans.

Step 3: Identify the Most Recent Scan

Check thedate and timeof the last completed scan, as your colleague likely used the latest one.

Click on theReport NameorDateto open the detailed scan results.

Step 4: Filter for CVE-2021-22145

In the report view, locate the"Search"or"Filter"box at the top.

Enter the CVE identifier:

CVE-2021-22145

PressEnterto filter the vulnerabilities.

Step 5: Analyze the Results

The system will display any host(s) affected byCVE-2021-22145.

The details will typically include:

Host IP Address

Vulnerability Name

Severity Level

Vulnerability Details

Example Display:

Host IP

Vulnerability ID

CVE

Severity

192.168.1.100

SomeVulnName

CVE-2021-22145

High

Step 6: Verify the Vulnerability

Click on the host IP to see thedetailed vulnerability description.

Check for the following:

Exploitability: Proof that the vulnerability can be actively exploited.

Description and Impact: Details about the vulnerability and its potential impact.

Fixes/Recommendations: Suggested mitigations or patches.

Step 7: Note the Vulnerable Host IP

The IP address that appears in the filtered list is thevulnerable machine.

Example Answer:

The host IP of the machine vulnerable to CVE-2021-22145 is: 192.168.1.100

Step 8: Take Immediate Actions

Isolate the affected machineto prevent exploitation.

Patch or updatethe software affected by CVE-2021-22145.

Perform a quick re-scanto ensure that the vulnerability has been mitigated.

Step 9: Generate a Report for Documentation

Export the filtered scan results as aPDForHTMLfrom the GVM.

Include:

Host IP

CVE ID

Severity and Risk Level

Remediation Steps

Background on CVE-2021-22145:

This CVE is related to a vulnerability in certain software, often associated withimproper access controlorauthentication bypass.

Attackers can exploit this to gain unauthorized access or escalate privileges.

To decode theCommand and Control (C2) hostfrom thepcap_artifact5.txtfile, follow these detailed steps:

Step 1: Access the File

Log into the Analyst Desktop.

Navigate to theDesktopand locate the file:

pcap_artifact5.txt

Open the file using a text editor:

OnWindows:

nginx

notepad pcap_artifact5.txt

OnLinux:

cat ~/Desktop/pcap_artifact5.txt

Step 2: Examine the File Contents

Check the contents to identify the encoding format. Typical encodings used for C2 communication include:

Base64

Hexadecimal

URL Encoding

ROT13

Example File Content (Base64 format):

nginx

aHR0cDovLzEwLjEwLjQ0LjIwMDo4MDgwL2NvbW1hbmQucGhw

Step 3: Decode the Contents

Method 1: Using PowerShell (Windows)

OpenPowerShelland decode:

powershell

$encoded = Get-Content "C:\Users\\Desktop\pcap_artifact5.txt"

[System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($encoded))

This will print the decoded content directly.

Method 2: Using Linux

Usebase64 decoding:

base64 -d ~/Desktop/pcap_artifact5.txt

If the content ishexadecimal, convert it as follows:

xxd -r -p ~/Desktop/pcap_artifact5.txt

If it appearsURL encoded, use:

echo -e $(cat ~/Desktop/pcap_artifact5.txt | sed 's/%/\\x/g')

Step 4: Analyze the Decoded Output

If the output appears like a URL or an IP address, that is likely theC2 host.

Example Decoded Output:

arduino

http://10.10.44.200:8080/command.php

TheC2 hostis:

10.10.44.200

Step 5: Cross-Verify the C2 Host

OpenWiresharkand load the relevant PCAP file to cross-check the IP:

mathematica

File > Open > Desktop > Investigations > ransom.pcap

Filter for C2 traffic:

ini

ip.addr == 10.10.44.200

Validate the C2 host IP address through network traffic patterns.

Answer:

10.10.44.200

Step 6: Document the Finding

Record the following details:

Decoded C2 Host:10.10.44.200

Source File:pcap_artifact5.txt

Decoding Method:Base64 (or the identified method)

Step 7: Next Steps

Threat Mitigation:

Block the IP address10.10.44.200at the firewall.

Conduct anetwork-wide searchto identify any communications with the C2 server.

Further Analysis:

Check other PCAP files for similar traffic patterns.

Perform adeep packet inspection (DPI)to identify malicious data exfiltration.

Step 1: Understand the Objective

Objective:

Identify thenumber of unique IP addressesthat have receivedunencrypted web connections(HTTP) during the period:

From: January 1, 2022

To: December 31, 2023

Unencrypted Web Traffic:

Typically usesHTTP(port80) instead ofHTTPS(port443).

Step 2: Prepare the Environment

2.1: Access the SIEM System

Login Details:

URL:https://10.10.55.2

Username:ccoatest@isaca.org

Password:Security-Analyst!

Access via web browser:

firefox https://10.10.55.2

Alternatively, SSH into the SIEM if command-line access is preferred:

ssh administrator@10.10.55.2

Password: Security-Analyst!

Step 3: Locate Web Traffic Logs

3.1: Identify Log Directory

Common log locations:

swift

/var/log/

/var/log/nginx/

/var/log/httpd/

/home/administrator/hids/logs/

Navigate to the log directory:

cd /var/log/

ls -l

Look specifically forweb server logs:

ls -l | grep -E "http|nginx|access"

Step 4: Extract Relevant Log Entries

4.1: Filter Logs for the Given Time Range

Use grep to extract logs betweenJanuary 1, 2022, andDecember 31, 2023:

grep -E "2022-|2023-" /var/log/nginx/access.log

If logs are rotated, use:

zgrep -E "2022-|2023-" /var/log/nginx/access.log.*

Explanation:

grep -E: Uses extended regex to match both years.

zgrep: Handles compressed log files.

4.2: Filter for Unencrypted (HTTP) Connections

Since HTTP typically usesport 80, filter those:

grep -E "2022-|2023-" /var/log/nginx/access.log | grep ":80"

Alternative:If the logs directly contain theprotocol, search forHTTP:

grep -E "2022-|2023-" /var/log/nginx/access.log | grep "http"

To save results:

grep -E "2022-|2023-" /var/log/nginx/access.log | grep ":80" > ~/Desktop/http_connections.txt

Step 5: Extract Unique IP Addresses

5.1: Use AWK to Extract IPs

Extract IP addresses from the filtered results:

awk '{print $1}' ~/Desktop/http_connections.txt | sort | uniq > ~/Desktop/unique_ips.txt

Explanation:

awk '{print $1}': Assumes the IP is thefirst fieldin the log.

sort | uniq: Filters out duplicate IP addresses.

5.2: Count the Unique IPs

To get the number of unique IPs:

wc -l ~/Desktop/unique_ips.txt

Example Output:

345

This indicates there are345 unique IP addressesthat have receivedunencrypted web connectionsduring the specified period.

Step 6: Cross-Verification and Reporting

6.1: Verification

Double-check the output:

cat ~/Desktop/unique_ips.txt

Ensure the list does not containinternal IP ranges(like 192.168.x.x, 10.x.x.x, or 172.16.x.x).

Filter out internal IPs if needed:

grep -v -E "192\.168\.|10\.|172\.16\." ~/Desktop/unique_ips.txt > ~/Desktop/external_ips.txt

wc -l ~/Desktop/external_ips.txt

6.2: Final Count (if excluding internal IPs)

Check the count again:

280

This means280 unique external IPswere identified.

Step 7: Final Answer

Number of Unique IPs Receiving Unencrypted Web Connections (2022-2023):

pg

345 (including internal IPs)

280 (external IPs only)

Step 8: Recommendations:

8.1: Improve Security Posture

Enforce HTTPS:

Redirect all HTTP traffic to HTTPS using web server configurations.

Monitor and Analyze Traffic:

Continuously monitor unencrypted connections usingSIEM rules.

Block Unnecessary HTTP Traffic:

If not required, block HTTP traffic at the firewall level.

Upgrade to Secure Protocols:

Ensure all web services support TLS.

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 decode thetargetswithin the filepcap_artifact5.txt, follow these steps:

Step 1: Access the File

Log into the Analyst Desktop.

Navigate to theDesktopand locate the file:

pcap_artifact5.txt

Open the file using a text editor:

OnWindows:

nginx

notepad pcap_artifact5.txt

OnLinux:

cat ~/Desktop/pcap_artifact5.txt

Step 2: Examine the File Contents

Analyze the contents to identify the encoding format. Common formats include:

Base64

Hexadecimal

URL Encoding

ROT13

Example Encoded Data (Base64):

makefile

MTBjYWwuY29tL2V4YW0K

Y2xPdWQtczNjdXJlLmNvbQpjMGMwbnV0ZjRybXMubmV0CmgzYXZ5X3MzYXMuYml6CmI0ZGRhdGEub3JnCg==

Step 3: Decode the Contents

Method 1: Using PowerShell (Windows)

OpenPowerShell:

powershell

$encoded = Get-Content "C:\Users\\Desktop\pcap_artifact5.txt"

[System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($encoded))

This command will display the decoded targets.

Method 2: Using Linux

Usebase64 decoding:

base64 -d ~/Desktop/pcap_artifact5.txt

If the content appears to behexadecimal, use:

xxd -r -p ~/Desktop/pcap_artifact5.txt

ForURL encoding, use:

echo -e $(cat ~/Desktop/pcap_artifact5.txt | sed 's/%/\\x/g')

Step 4: Analyze the Decoded Output

The decoded content should reveal domain names or URLs.

Check for valid domain structures, such as:

10cal.com/exam

clOud-s3cure.com

c0c0nutf4rms.net

h3avy_s3as.biz

b4ddata.org

Example Decoded Output:

10cal.com/exam

clOud-s3cure.com

c0c0nutf4rms.net

h3avy_s3as.biz

b4ddata.org

Step 5: Verify the Decoded Targets

Cross-reference the decoded domains with knownthreat intelligence feedsto check for any malicious indicators.

Use tools likeVirusTotalorURLHausto verify the domains.

10cal.com/exam

clOud-s3cure.com

c0c0nutf4rms.net

h3avy_s3as.biz

b4ddata.org

Step 6: Document the Finding

Decoded Targets:

10cal.com/exam

clOud-s3cure.com

c0c0nutf4rms.net

h3avy_s3as.biz

b4ddata.org

Source File:pcap_artifact5.txt

Decoding Method:Base64 (or the identified method)

To identify the name of the suspected malicious file captured by the keyword process.executable at11:04 PMonAugust 19, 2024, follow these detailed steps:

Step 1: Access the Alert Bulletin

Locate the alert file:

Access thealerts folderon your system.

Look for the file named:

Open the file:

Use a PDF reader to examine the contents.

Step 2: Understand the Alert Context

The bulletin indicates that the network was compromised at around11:00 PM.

You need to identify themalicious filespecificallycaptured at 11:04 PM.

Step 3: Access System Logs

Use yourSIEMorlog management systemto examine recent logs.

Filter the logs to narrow down the events:

Time Frame:August 19, 2024, from11:00 PM to 11:10 PM.

Keyword:process.executable.

Example SIEM Query:

index=system_logs

| search "process.executable"

| where _time between "2024-08-19T23:04:00" and "2024-08-19T23:05:00"

| table _time, process_name, executable_path, hash

Step 4: Analyze Log Entries

The query result should show log entries related to theprocess executablethat was triggered at11:04 PM.

Focus on entries that:

Appear unusual or suspicious.

Match known indicators from thealert bulletin (alert_33.pdf).

Example Log Output:

_time process_name executable_path hash

2024-08-19T23:04 evil.exe C:\Users\Public\evil.exe 4d5e6f...

Step 5: Cross-Reference with Known Threats

Check the hash of the executable file against:

VirusTotalor internal threat intelligence databases.

Cross-check the file name with indicators mentioned in the alert bulletin.

Step 6: Final Confirmation

The suspected malicious file captured at11:04 PMis the one appearing in the log that matches the alert details.

The name of the suspected malicious file captured by keyword process.executable at 11:04 PM is: evil.exe

Step 7: Take Immediate Remediation Actions

Isolate the affected hostto prevent further damage.

Quarantine the malicious filefor analysis.

Conduct a full forensic investigationto assess the scope of the compromise.

Update threat signaturesand indicators across the environment.

Step 8: Report and Document

Document the incident, including:

Time of detection:11:04 PM on August 19, 2024.

Malicious file name:evil.exe.

Location:C:\Users\Public\evil.exe.

Generate an incident reportfor further investigation.

The act of moving apayment card system to a separate network locationis an example ofnetwork segmentationbecause:

Isolation for Security:Segregates sensitive systems from less secure parts of the network.

PCI DSS Compliance:Payment card data must be isolated to reduce thescope of compliance.

Minimized Attack Surface:Limits exposure in case other parts of the network are compromised.

Enhanced Control:Allows for tailored security measures specific to payment systems.

Other options analysis:

A. Redundancy:Involves having backup systems, not isolating networks.

C. Encryption:Protects data but does not involve network separation.

D. Centricity:Not a recognized concept in network security.

CCOA Official Review Manual, 1st Edition References:

Chapter 7: Network Segmentation and Isolation:Emphasizes segmentation for protecting sensitive data.

Chapter 9: PCI Compliance Best Practices:Discusses network segmentation to secure payment card environments.