Lateral Movement: Threat Hunting “Processes Launching cmd.exe”

Lateral Movement: Threat Hunting “Processes Launching cmd.exe” 

Many lateral movement techniques rely on system utilities like cmd.exe to blend in with legitimate activities. This post examines how malicious actors misuse the Windows Command Prompt to move through networks and escalate privileges.

Scenario Background

Use Case: Processes Launching cmd.exe
Tactic: Situational Awareness
MITRE Reference: CAR-2013-02-003 (Processes Spawning cmd.exe)

cmd.exe is a core utility in Windows, allowing users to run programs, batch scripts, and built-in commands. Typically, the parent process is explorer.exe (when a user manually opens a Command Prompt) or another command shell.

Hypothesis

Malicious activity can be identified when cmd.exe is spawned by unexpected processes, suggesting exploitation through malicious documents or compromised applications.

Real-World Example

In a recent ransomware outbreak, attackers sent phishing emails with malicious attachments disguised as PDF invoices. When the victim opened the file, the malicious PDF triggered Adobe Reader to spawn cmd.exe with hidden parameters:

1. Phishing PDF: The user opened a file in Adobe Reader.
2. cmd.exe Launch: The malicious script inside the PDF exploited a known vulnerability to spawn cmd.exe (parent process: Adobe Reader).
3. Lateral Movement: Using the newly spawned shell, attackers executed network scans and credential harvesting tools, eventually compromising multiple servers.

This anomaly—cmd.exe launched by Adobe Reader—alerted the security team to a possible infection and led to a swift containment of the threat.

Detection Strategy

• Filtering Parent Processes: Identify cmd.exe events where the parent process is not explorer.exe.
• Process Tree Analysis: Investigate whether cmd.exe was spawned by commonly abused applications (e.g., browsers, PDF readers, email clients).
• Behavioral Analysis: Use baseline data to distinguish administrative tasks (e.g., software installation scripts) from malicious usage of cmd.exe.

Combined with robust logging and EDR capabilities, monitoring unexpected process spawns can surface malicious lateral movement activities. In the next post, we’ll discuss strategies for detecting lateral movement at scale, crucial for enterprise-level security operations centers (SOCs).