Emotet Resurgence: Fake Invoice Emails Deliver Malware Payloads – Full Detection & Mitigation Guide

Emotet Fake Invoice Malware

Emotet Fake Invoice Malware is back and it has become more dangerous than ever! This notorious malware has returned through a massive email phishing campaign sending fake invoices to unsuspecting employees. With one click macros execute malicious scripts that download Emotet open backdoors for Cobalt Strike and lead to ransomware attacks.

Why It Matters:

• Impact: Emotet enables lateral movement, steals credentials using Mimikatz and deploys ransomware payloads like Ryuk or Conti.

• Target: Enterprises, government agencies & SMBs worldwide.

2. Attack Flow – How Emotet Fake Invoice Malware Spreads

Let’s break down how attackers leverage Emotet step-by-step:

Step-by-Step Breakdown

Phishing Emails:

• Emails contain malicious Word documents disguised as invoices.

• Subject lines:

  • Invoice Due: Please Review

  • Payment Confirmation Required

Malicious Macro Execution:

• When users open the Word document and enable macros, VBA code runs hidden PowerShell scripts.

Payload Delivery:

• Emotet downloads additional tools, such as:

  • Cobalt Strike: For persistence and lateral movement.

  • Mimikatz: To extract credentials.

Lateral Movement and Deployment:

• Emotet moves across systems using stolen credentials.

• Secondary payloads like ransomware are deployed.

3. Indicators of Compromise (IoCs)

Here are key IoCs to detect Emotet activity:

File Hashes

• Malicious Word Doc:

  • d6e05ab5c1e8ab39e19c8fa7a9d56471

• Emotet Payload:

  • 8f23c1276c2b54f89aef6c1234abcd12

Malicious IPs

• 203.0.113.45

• 198.51.100.23

• 192.0.2.18

Suspicious Processes

• winword.exe spawning powershell.exe

• regsvr32.exe being used for DLL execution.

4. Detection Scripts

1. Detect PowerShell Executions Triggered by Word (Macros)

Use this PowerShell script to monitor PowerShell activity initiated by Word documents:

# Detect PowerShell processes started by Word Get-WinEvent -LogName Security -FilterXPath "*[System[Provider[@Name='Microsoft-Windows-Security-Auditing'] and EventID=4688] and EventData[Data[@Name='NewProcessName'] and (contains(.,'powershell.exe'))] and EventData[Data[@Name='ParentProcessName'] and contains(.,'winword.exe')]]" | Select-Object TimeCreated, Message

2. Check for Known Malicious Emotet Domains and IPs

Run this script to compare active connections against known IoCs:

# Replace with the list of malicious IPs $MaliciousIPs = @("203.0.113.45", "198.51.100.23", "192.0.2.18") # Check active connections $Connections = Get-NetTCPConnection | Where-Object { $_.RemoteAddress -in $MaliciousIPs } if ($Connections) { Write-Host "ALERT: Connection to known Emotet IPs detected!" -ForegroundColor Red $Connections } else { Write-Host "No suspicious connections found." -ForegroundColor Green }

3. Detect DLL Execution via regsvr32 (Emotet Behavior)

Emotet often uses regsvr32.exe to load malicious DLLs. Use this script to monitor such activities:

# Monitor regsvr32 for malicious DLL executions Get-WinEvent -LogName Security -FilterXPath "*[System[Provider[@Name='Microsoft-Windows-Security-Auditing'] and EventID=4688] and EventData[Data[@Name='NewProcessName'] and contains(.,'regsvr32.exe')]]" | Select-Object TimeCreated, Message

5. Mitigation Steps – Secure Your Network

Follow these steps to defend against Emotet campaigns:

- Disable Macros by Default

• In Microsoft Office, set macros to Disable all macros with notification

- Implement Email Filtering

• Block suspicious file types like .doc, .xls, and .exe.

• We can use tools such Proofpoint or Mimecast to filter phishing emails.

- Endpoint Detection and Response

• Deploy Microsoft Defender for Endpoint, CrowdStrike or SentinelOne to detect macro-based attacks.

- Monitor Network Traffic

• Look for outbound connections to known Emotet C2 servers (IPs listed above).

- Patch Systems

• Ensure all systems and Office apps are up-to-date to prevent exploit chains.

- Train Employees

• Conduct regular phishing simulations to educate employees about suspicious emails.

  
  

The return of Emotet shows that phishing campaigns are still a powerful tool for attackers. By disabling macros, monitoring suspicious processes, and using detection scripts, you can protect your organization from this evolving threat.

For full IoCs, advanced scripts, and detailed mitigation steps, check out my guide 👉aakashrahsi.online/vulnerabilities"

Stay Secure. Stay Ahead.

The content provided in this article, including analysis, scripts, and mitigation steps, is the result of independent research and expertise by Aakash Rahsi. While the information may include publicly known vulnerabilities or threats, the presentation, explanations, and solutions are original work by the author. This article is intended for educational and informational purposes only. Sharing is encouraged with proper credit to the author. Unauthorized reproduction for commercial purposes is strictly prohibited.