Eventcode 4104, also known as Windows Security Event ID 4104, signifies scriptblock logging within a system's security logs. This vital event is generated when PowerShell script code is executed and contains terms deemed suspicious or potentially malicious.
Understanding Event ID 4104: Scriptblock Logging
Scriptblock logging is a crucial security feature in Windows environments, designed to provide deep visibility into PowerShell operations. It is enabled by default on modern Windows systems, making it an immediate source of valuable security intelligence without requiring additional configuration.
This logging mechanism captures the content of PowerShell script blocks as they are processed. It specifically targets and records script code that includes a predefined list of suspicious terms. This list is maintained by Microsoft and encompasses the majority of cmdlets (command-lets) that are commonly abused by attackers for various malicious activities, such as:
- Execution of malware
- Information gathering
- Privilege escalation
- Persistence mechanisms
By logging these specific code segments, Event ID 4104 helps administrators and security professionals detect sophisticated threats that leverage PowerShell, which is a powerful and often legitimate administrative tool frequently exploited by adversaries.
Key Aspects of Event ID 4104
To summarize the core characteristics of this important event ID:
| Feature | Description |
|---|---|
| Event ID | 4104 |
| Category | Windows Security Event / PowerShell Logging |
| Logging Type | Scriptblock Logging |
| Default State | Enabled (Automatic) |
| Content Logged | PowerShell script code containing suspicious terms, including commonly abused cmdlets. |
| Primary Purpose | Enhance security monitoring, detect malicious PowerShell activity, and aid in incident response. |
Significance for Security and Threat Detection
Event ID 4104 plays a critical role in an organization's security posture. Its automatic activation and detailed logging provide several benefits:
- Early Threat Detection: By recording suspicious PowerShell activity, this event can alert security systems to potential attacks in progress, even those attempting to evade traditional signature-based detection.
- Forensic Analysis: In the event of a breach or suspicious activity, the logs generated by Event ID 4104 serve as invaluable forensic artifacts. They can reveal the exact PowerShell commands executed by an attacker, helping investigators understand the scope and nature of an incident.
- Behavioral Monitoring: Security teams can use these logs to establish a baseline of normal PowerShell behavior. Any deviations, particularly the presence of commonly abused cmdlets in unusual contexts, can trigger alerts for further investigation.
- Compliance and Auditing: For regulatory compliance, having a robust logging mechanism for scripting activities provides an auditable trail of system interactions, which can be essential for demonstrating security controls.
Practical Insights
Leveraging Event ID 4104 effectively requires integrating these logs into a comprehensive security information and event management (SIEM) system. This allows for:
- Real-time Alerting: Configure alerts for specific patterns or quantities of 4104 events that might indicate malicious activity.
- Correlation: Correlate Event ID 4104 with other security events (e.g., process creation, network connections) to build a complete picture of an attack chain.
- Hunting for Threats: Proactively search through logs for specific PowerShell commands or techniques known to be used by threat actors.
Understanding and actively monitoring Event ID 4104 is a cornerstone of effective defense against modern, file-less, and script-based attacks that increasingly rely on legitimate system tools like PowerShell.
