CCOA Practice Questions

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 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:

READM

E.  

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/READM

E.  

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:

READM

E.  

Step 7: Confirm and Document

File Name:READM

E.  

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:READM

E.  

txt

Method of Delivery:HTTP (or SMB)

Ransomware Message:Payment in Bitcoin

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

To create a new case inSecurity Onionusing the logs from the win-webserver01_logs.zip file, follow these detailed steps:

Step 1: Access Security Onion

Open a web browser and go to yourSecurity Onionweb interface.

URL: https:// /

Log in using yourSecurity Onioncredentials.

Step 2: Prepare the Log File

Navigate to theDesktopand open theInvestigationsfolder.

Locate the file:

win-webserver01_logs.zip

Unzip the file to inspect its contents:

unzip ~/Desktop/Investigations/win-webserver01_logs.zip -d ~/Desktop/Investigations/win-webserver01_logs

Ensure that the extracted files, including System-logs.evtx, are accessible.

Step 3: Open the Hunt Interface in Security Onion

On the Security Onion dashboard, go to"Hunt"(or"Cases"depending on the version).

Click on"Cases"to manage incident cases.

Step 4: Create a New Case

Click on"New Case"to start a fresh investigation.

Case Details:

Title:

Windows Webserver Logs - CCOA New Case

TLP (Traffic Light Protocol):

Set toGreen(indicating that the information can be shared freely).

Example Configuration:

Field

Value

Title

Windows Webserver Logs - CCOA New Case

TLP

Green

Summary

(Leave blank if not required)

Click"Save"to create the case.

Step 5: Upload the Log Files

After creating the case, go to the"Files"section of the new case.

Click on"Upload"and select the unzipped log file:

~/Desktop/Investigations/win-webserver01_logs/System-logs.evtx

Once uploaded, the file will be associated with the case.

Step 6: Verify the Case Creation

Go back to theCasesdashboard.

Locate and verify that the case"Windows Webserver Logs - CCOA New Case"exists withTLP: Green.

Check that thelog filehas been successfully uploaded.

Step 7: Document and Report

Document the case details:

Case Title:Windows Webserver Logs - CCOA New Case

TLP:Green

Log File:System-logs.evtx

Include anyinitial observationsfrom the log analysis.

Example Answer:

A new case titled "Windows Webserver Logs - CCOA New Case" with TLP set to Green has been successfully created in Security Onion. The log file System-logs.evtx has been uploaded and linked to the case.

Step 8: Next Steps for Investigation

Analyze the log file:Start hunting for suspicious activities.

Create analysis tasks:Assign team members to investigate specific log entries.

Correlate with other data:Cross-reference with threat intelligence sources.

To decode the contents of the filepcap_artifact5.txtand save the output in a new file namedpcap_artifact5_decoded.txt, 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

Analyze the content to identify the encoding format. Common encoding types include:

Base64

Hexadecimal

URL Encoding

ROT13

Example File Content:

ini

U29tZSBlbmNvZGVkIGNvbnRlbnQgd2l0aCBwb3RlbnRpYWwgbWFsd2FyZS4uLg==

The above example appears to beBase64 encoded.

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)) | Out-File "C:\Users\\Desktop\pcap_artifact5_decoded.txt"

Method 2: Using Command Prompt (Windows)

Usecertutilfor Base64 decoding:

cmd

certutil -decode pcap_artifact5.txt pcap_artifact5_decoded.txt

Method 3: Using Linux/WSL

Use thebase64decoding command:

base64 -d ~/Desktop/pcap_artifact5.txt > ~/Desktop/pcap_artifact5_decoded.txt

If the content isHexadecimal, use:

xxd -r -p ~/Desktop/pcap_artifact5.txt > ~/Desktop/pcap_artifact5_decoded.txt

Step 4: Verify the Decoded File

Open the decoded file to verify its contents:

OnWindows:

php-template

notepad C:\Users\\Desktop\pcap_artifact5_decoded.txt

OnLinux:

cat ~/Desktop/pcap_artifact5_decoded.txt

Check if the decoded text makes sense and is readable.

Example Decoded Output:

Some encoded content with potential malware...

Step 5: Save and Confirm

Ensure the file is saved as:

pcap_artifact5_decoded.txt

Located on theDesktopfor easy access.

Step 6: Analyze the Decoded Content

Look for:

Malware signatures

Command and control (C2) server URLs

Indicators of Compromise (IOCs)

Step 7: Document the Process

Record the following:

Original Filename:pcap_artifact5.txt

Decoded Filename:pcap_artifact5_decoded.txt

Decoding Method:Base64 (or identified method)

Contents:Brief summary of findings

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)