Authentic Isaca Certification Exam CCOA Questions Answers

To determine thedate the webshell was accessedfrom theinvestigation22.pcapfile, follow these detailed steps:

Step 1: Access the PCAP File

Log into the Analyst Desktop.

Navigate to theInvestigationsfolder on the desktop.

Locate the file:

investigation22.pcap

Step 2: Open the PCAP File in Wireshark

LaunchWireshark.

Open the PCAP file:

mathematica

File > Open > Desktop > Investigations > investigation22.pcap

ClickOpento load the file.

Step 3: Filter for Webshell Traffic

Since webshells typically useHTTP/Sto communicate, apply a filter:

http.request or http.response

Alternatively, if you know the IP of the compromised host (e.g.,10.10.44.200), use:

nginx

http and ip.addr == 10.10.44.200

PressEnterto apply the filter.

Step 4: Identify Webshell Activity

Look for HTTP requests that include:

Common Webshell Filenames:shell.jsp, cmd.php, backdoor.aspx, etc.

Suspicious HTTP Methods:MainlyPOSTorGET.

Right-click a suspicious packet and choose:

arduino

Follow > HTTP Stream

Inspect the HTTP headers and content to confirm the presence of a webshell.

Step 5: Extract the Access Date

Look at theHTTP request/response header.

Find theDatefield orTimestampof the packet:

Wireshark displays timestamps on the left by default.

Confirm theHTTP streamincludes commands or uploads to the webshell.

Example HTTP Stream:

POST /uploads/shell.jsp HTTP/1.1

Host: 10.10.44.200

User-Agent: Mozilla/5.0

Date: Mon, 2024-03-18 14:35:22 GMT

Step 6: Verify the Correct Date

Double-check other HTTP requests or responses related to the webshell.

Make sure thedate fieldis consistent across multiple requests to the same file.

Answer:

2024-03-18

Step 7: Document the Finding

Date of Access:2024-03-18

Filename:shell.jsp (as identified earlier)

Compromised Host:10.10.44.200

Method of Access:HTTP POST

Step 8: Next Steps

Isolate the Affected Host:

Remove the compromised server from the network.

Remove the Webshell:

rm /path/to/webshell/shell.jsp

Analyze Web Server Logs:

Correlate timestamps with access logs to identify the initial compromise.

Implement WAF Rules:

Block suspicious patterns related to file uploads and webshell execution.

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:

https://10.10.55.2

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

Step 1: Understand the Objective

Objective:

Identify thedomain name(s)that werecontactedbetween:

12:10 AM to 12:12 AM on August 17, 2024

Source of information:

CCOA Threat Bulletin.pdf

File location:

~/Desktop/CCOA Threat Bulletin.pdf

Step 2: Prepare for Investigation

2.1: Ensure Access to the File

Check if the PDF exists:

ls ~/Desktop | grep "CCOA Threat Bulletin.pdf"

Open the file to inspect:

xdg-open ~/Desktop/CCOA\ Threat\ Bulletin.pdf

Alternatively, convert to plain text for easier analysis:

pdftotext ~/Desktop/CCOA\ Threat\ Bulletin.pdf ~/Desktop/threat_bulletin.txt

cat ~/Desktop/threat_bulletin.txt

2.2: Analyze the Content

Look for domain names listed in the bulletin.

Make note ofany domainsorURLsmentioned as IoCs (Indicators of Compromise).

Example:

suspicious-domain.com

malicious-actor.net

threat-site.xyz

Step 3: Locate Network Logs

3.1: Find the Logs Directory

The logs could be located in one of the following directories:

/var/log/

/home/administrator/hids/logs/

/var/log/httpd/

/var/log/nginx/

Navigate to the likely directory:

cd /var/log/

ls -l

Identify relevant network or DNS logs:

ls -l | grep -E "dns|network|http|nginx"

Step 4: Search Logs for Domain Contacts

4.1: Use the Grep Command to Filter Relevant Timeframe

Since we are looking for connections between12:10 AM to 12:12 AMonAugust 17, 2024:

grep "2024-08-17 00:1[0-2]" /var/log/dns.log

Explanation:

grep "2024-08-17 00:1[0-2]": Matches timestamps between00:10and00:12.

Replace dns.log with the actual log file name, if different.

4.2: Further Filter for Domain Names

To specifically filter out the domains listed in the bulletin:

grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)" /var/log/dns.log

If the logs are in another file, adjust the file path:

grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)" /var/log/nginx/access.log

Step 5: Correlate Domains and Timeframe

5.1: Extract and Format Relevant Results

Combine the commands to get time-specific domain hits:

grep "2024-08-17 00:1[0-2]" /var/log/dns.log | grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)"

Sample Output:

2024-08-17 00:11:32 suspicious-domain.com accessed by 192.168.1.50

2024-08-17 00:12:01 malicious-actor.net accessed by 192.168.1.75

Interpretation:

The command revealswhich domain(s)were contacted during the specified time.

Step 6: Verification and Documentation

6.1: Verify Domain Matches

Cross-check the domains in the log output against those listed in theCCOA Threat Bulletin.pdf.

Ensure that the time matches the specified range.

6.2: Save the Results for Reporting

Save the output to a file:

grep "2024-08-17 00:1[0-2]" /var/log/dns.log | grep -E "(suspicious-domain.com|malicious-actor.net|threat-site.xyz)" > ~/Desktop/domain_hits.txt

Review the saved file:

cat ~/Desktop/domain_hits.txt

Step 7: Report the Findings

Final Answer:

Domain(s) Contacted:

suspicious-domain.com

malicious-actor.net

Time of Contact:

Between 12:10 AM to 12:12 AM on August 17, 2024

Reasoning:

Matched thelog timestampsanddomain nameswith the threat bulletin.

Step 8: Recommendations:

Immediate Block:

Add the identified domains to theblockliston firewalls and intrusion detection systems.

Monitor for Further Activity:

Keep monitoring logs for any further connection attempts to the same domains.

Perform IOC Scanning:

Check hosts that communicated with these domains for possible compromise.

Incident Report:

Document the findings and mitigation actions in theincident response log.