Threat Detection and Hunting Techniques for Windows
This section provides detailed guidance on identifying and responding to sophisticated threats within your Windows environments. Effective threat hunting requires a deep understanding of system behaviors, logging capabilities, and attack methodologies.
Introduction to Threat Hunting
Threat hunting is a proactive cybersecurity practice that involves searching for evidence of malicious activity that may have evaded automated security defenses. It's an iterative process that leverages threat intelligence, analytics, and deep system knowledge to uncover hidden threats.
Key Areas of Focus
- Endpoint Monitoring: Analyzing process execution, file system changes, registry modifications, and network connections on Windows endpoints.
- Log Analysis: Correlating events from various log sources, including Windows Event Logs (Security, System, Application), Sysmon, and network device logs.
- Network Traffic Analysis: Identifying anomalous network patterns, command-and-control (C2) communications, and lateral movement.
- Memory Forensics: Examining process memory for malicious code, injected threads, and stolen credentials.
Common Attack Techniques and Hunting Strategies
Technique Category: Execution
Process Injection
Look for processes that are injecting code into other legitimate processes, such as svchost.exe or explorer.exe. Monitor for unusual parent-child process relationships and API call patterns.
Scheduled Tasks
Hunt for newly created or modified scheduled tasks, especially those that execute with elevated privileges or run from unusual locations.
PowerShell Abuse
Analyze PowerShell execution logs (Event ID 4103, 4104) for obfuscated scripts, suspicious commands, or remote execution (e.g., Invoke-Command).
Technique Category: Persistence
Registry Run Keys
Monitor changes to Run keys in the registry (HKCU\...\Run, HKLM\...\Run) for persistence mechanisms.
WMI Event Subscription
Investigate WMI consumers and filters for persistence. Look for unexpected event filters and the scripts they trigger.
Technique Category: Credential Access
LSASS Memory Dumping
Detect attempts to access the Local Security Authority Subsystem Service (LSASS) process memory, often indicated by processes like mimikatz or related tools.
Credential Manipulation
Monitor for modifications to user accounts, password policies, or the creation of new administrative accounts.
Technique Category: Lateral Movement
Remote Service Creation
Identify the creation of new Windows services that are configured to run remotely or start on demand.
SMB/RDP Activity
Analyze network logs for unusual SMB or RDP connections between workstations, especially those originating from non-administrative users.
Tools and Resources
- Sysmon: A powerful tool for monitoring and logging system activity. Configure Sysmon with detailed rules for effective hunting. Learn More about Sysmon Configuration
- Windows Event Logs: Leverage Event Viewer and PowerShell cmdlets to collect and analyze security-relevant events.
- PowerShell: Essential for automating data collection, analysis, and response actions.
- Third-Party EDR/SIEM Solutions: Integrate these tools for advanced threat detection and centralized log management.
Best Practices for Threat Hunting
- Develop Hypotheses: Start with specific assumptions about potential threats based on threat intelligence.
- Know Your Environment: Understand what "normal" looks like in your network to identify anomalies.
- Automate Where Possible: Use scripting and tools to collect and pre-process data efficiently.
- Document Findings: Keep detailed records of your hunts, findings, and remediation steps.
- Stay Updated: Continuously learn about new attack techniques and security best practices.