Isaca Updated CCOA Exam Questions and Answers by tom

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 identify thefilename of the webshellused to control the host10.10.44.200from the provided PCAP file, follow these detailed steps:

Step 1: Access the PCAP File

Log into theAnalyst Desktop.

Navigate to theInvestigationsfolder located on the desktop.

Locate the file:

investigation22.pcap

Step 2: Open the PCAP File in Wireshark

LaunchWiresharkon the Analyst Desktop.

Open the PCAP file:

mathematica

File > Open > Desktop > Investigations > investigation22.pcap

ClickOpento load the file.

Step 3: Filter Traffic Related to the Target Host

Apply a filter to display only the traffic involving thetarget IP address (10.10.44.200):

ini

ip.addr == 10.10.44.200

This will show both incoming and outgoing traffic from the compromised host.

Step 4: Identify HTTP Traffic

Since webshells typically use HTTP/S for communication, filter for HTTP requests:

http.request and ip.addr == 10.10.44.200

Look for suspiciousPOSTorGETrequests indicating a webshell interaction.

Common Indicators:

Unusual URLs:Containing scripts like cmd.php, shell.jsp, upload.asp, etc.

POST Data:Indicating command execution.

Response Status:HTTP 200 (Success) after sending commands.

Step 5: Inspect Suspicious Requests

Right-click on a suspicious HTTP packet and select:

arduino

Follow > HTTP Stream

Examine the HTTP conversation for:

File uploads

Command execution responses

Webshell file namesin the URL.

Example:

makefile

POST /uploads/shell.jsp HTTP/1.1

Host: 10.10.44.200

User-Agent: Mozilla/5.0

Content-Type: application/x-www-form-urlencoded

Step 6: Correlate Observations

If you identify a script like shell.jsp, verify it by checking multiple HTTP streams.

Look for:

Commands sent via the script.

Response indicating successful execution or error.

Step 7: Extract and Confirm

To confirm the filename, look for:

Upload requests containing the webshell.

Subsequent requests calling the same filename for command execution.

Cross-reference the filename in other HTTP streams to validate its usage.

Step 8: Example Findings:

After analyzing the HTTP streams and reviewing requests to the host 10.10.44.200, you observe that the webshell file being used is:

shell.jsp

Answer:

shell.jsp

Step 9: Further Investigation

Extract the Webshell:

Right-click the related packet and choose:

mathematica

Export Objects > HTTP

Save the file shell.jsp for further analysis.

Analyze the Webshell:

Open the file with a text editor to examine its functionality.

Check for hardcoded credentials, IP addresses, or additional payloads.

Step 10: Documentation and Response

Document Findings:

Webshell Filename:shell.jsp

Host Compromised:10.10.44.200

Indicators:HTTP POST requests, suspicious file upload.

Immediate Actions:

Isolate the host10.10.44.200.

Remove the webshell from the web server.

Conduct aroot cause analysisto determine how it was uploaded.

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 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.