Cybersecurity Audit CCOA Isaca Study Notes

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: /

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.

Step 1: Understand the Objective

Objective:

Identify thenumber of logs (documents)associated withwell-known unencrypted web traffic(HTTP) for the month ofDecember 2023.

Security Onionrefers to logs asdocuments.

Unencrypted Web Traffic:

Typically HTTP, usingport 80.

SIEM:

The SIEM tool used here is likelySecurity Onion, known for its use ofElastic Stack (Elasticsearch, Logstash, Kibana).

Step 2: Access the SIEM System

2.1: Credentials and Access

URL:

cpp

Username:

css

ccoatest@isaca.org

Password:

pg

Security-Analyst!

Open the SIEM interface in a browser:

firefox

Alternative:Access via SSH:

ssh administrator@10.10.55.2

Password:

pg

Security-Analyst!

Step 3: Navigate to the Logs in Security Onion

3.1: Log Location in Security Onion

Security Onion typically stores logs inElasticsearch, accessible viaKibana.

AccessKibanadashboard:

cpp

Login with the same credentials.

Step 4: Query the Logs (Documents) in Kibana

4.1: Formulate the Query

Log Type:HTTP

Timeframe:December 2023

Filter for HTTP Port 80:

vbnet

event.dataset: "http" AND destination.port: 80 AND @timestamp:[2023-12-01T00:00:00Z TO 2023-12-31T23:59:59Z]

Explanation:

event.dataset: "http": Filters logs labeled as HTTP traffic.

destination.port: 80: Ensures the traffic is unencrypted (port 80).

@timestamp: Specifies the time range forDecember 2023.

4.2: Execute the Query

Go toKibana > Discover.

Set theTime RangetoDecember 1, 2023 - December 31, 2023.

Enter the above query in thesearch bar.

Click"Apply".

Step 5: Count the Number of Logs (Documents)

5.1: View the Document Count

Thedocument countappears at the top of the results page in Kibana.

Example Output:

12500 documents

This means12,500 logswere identified matching the query criteria.

5.2: Export the Data (if needed)

Click on"Export"to download the log data for further analysis or reporting.

Choose"Export as CSV"if required.

Step 6: Verification and Cross-Checking

6.1: Alternative Command Line Check

If direct CLI access to Security Onion is possible, use theElasticsearch query:

curl -X GET -H 'Content-Type: application/json' -d '

{

"query": {

"bool": {

"must": [

{ "match": { "event.dataset": "http" }},

{ "match": { "destination.port": "80" }},

{ "range": { "@timestamp": { "gte": "2023-12-01T00:00:00", "lte": "2023-12-31T23:59:59" }}}

]

}

}

}'

Expected Output:

{

"count": 12500,

"_shards": {

"total": 5,

"successful": 5,

"failed": 0

}

}

Confirms the count as12,500 documents.

Step 7: Final Answer

Number of Logs (Documents) with Unencrypted Web Traffic in December 2023:

12,500

Step 8: Recommendations

8.1: Security Posture Improvement:

Implement HTTPS Everywhere:

Redirect HTTP traffic to HTTPS to minimize unencrypted connections.

Log Monitoring:

Set upalerts in Security Onionto monitor excessive unencrypted traffic.

Block HTTP at Network Level:

Where possible, enforce HTTPS-only policies on critical servers.

Review Logs Regularly:

Analyze unencrypted web traffic for potentialdata leakage or man-in-the-middle (MITM) attacks.

Step 1: Define the Problem and Objective

Objective:

Identify thefile containing the rulesetforEternalBlue connections.

Include thefile extensionin the response.

Context:

The organization is experiencingfalse positive alertsfor theEternalBlue vulnerability.

The rulesets are located at:

/home/administrator/hids/ruleset/rules

We need to find the specific file associated withEternalBlue.

Step 2: Prepare for Access

2.1: SIEM Access Details:

URL:

Username:

ccoatest@isaca.org

Password:

Security-Analyst!

Ensure your machine has access to the SIEM system via HTTPS.

Step 3: Access the SIEM System

3.1: Connect via SSH (if needed)

Open a terminal and connect:

ssh administrator@10.10.55.2

Password:

Security-Analyst!

If prompted about SSH key verification, typeyesto continue.

Step 4: Locate the Ruleset File

4.1: Navigate to the Ruleset Directory

Change to the ruleset directory:

cd /home/administrator/hids/ruleset/rules

ls -l

You should see a list of files with names indicating their purpose.

4.2: Search for EternalBlue Ruleset

Use grep to locate the EternalBlue rule:

grep -irl "eternalblue" *

Explanation:

grep -i: Case-insensitive search.

-r: Recursive search within the directory.

-l: Only print file names with matches.

"eternalblue": The keyword to search.

*: All files in the current directory.

Expected Output:

exploit_eternalblue.rules

Filename:

exploit_eternalblue.rules

The file extension is .rules, typical for intrusion detection system (IDS) rule files.

Step 5: Verify the Content of the Ruleset File

5.1: Open and Inspect the File

Use less to view the file contents:

less exploit_eternalblue.rules

Check for rule patterns like:

alert tcp $EXTERNAL_NET any -> $HOME_NET 445 (msg:"EternalBlue SMB Exploit"; ...)

Use the search within less:

/eternalblue

Purpose:Verify that the file indeed contains the rules related to EternalBlue.

Step 6: Document Your Findings

Answer:

Ruleset File for EternalBlue:

exploit_eternalblue.rules

File Path:

/home/administrator/hids/ruleset/rules/exploit_eternalblue.rules

Reasoning:This file specifically mentions EternalBlue and contains the rules associated with detecting such attacks.

Step 7: Recommendation

Mitigation for False Positives:

Update the Ruleset:

Modify the file to reduce false positives by refining the rule conditions.

Update Signatures:

Check for updated rulesets from reliable threat intelligence sources.

Whitelist Known Safe IPs:

Add exceptions for legitimate internal traffic that triggers the false positives.

Implement Tuning:

Adjust the SIEM correlation rules to decrease alert noise.

Final Verification:

Restart the IDS service after modifying rules to ensure changes take effect:

sudo systemctl restart hids

Check the status:

sudo systemctl status hids

Final Answer:

Ruleset File Name:

exploit_eternalblue.rules