Custom alerts within the CrowdStrike Falcon platform, formally known as Custom Indicators of Attack (IOAs), are created by defining rules that act as triggers. These rules monitor the real-time stream of endpoint event data for specific, user-defined patterns of behavior. When a sequence of events matches the logic defined in the custom rule, the trigger is activated, and a custom alert is generated. This allows security teams to create tailored detections for threats, compliance requirements, or suspicious activities unique to their environment, supplementing CrowdStrike's built-in detections.

A. Custom workflows are automated response actions that can be initiated after an alert is generated, not the basis for the alert itself.

C. Predefined alert templates may serve as a starting point, but the core of a custom alert is the unique, user-defined logic, not the pre-existing template.

D. CrowdStrike Falcon uses its proprietary Falcon Query Language (FQL) for searching and defining rules, not Splunk's Search Processing Language (SPL).

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1. CrowdStrike

Inc. (2023). Falcon Platform: Custom IOAs. CrowdStrike Falcon Documentation.

Section: "Creating a rule"

Reference: The documentation explicitly states

"A rule is composed of a pattern that describes the behavior you want to detect... When Falcon observes the pattern on a host

it triggers a detection." This confirms that custom alerts are based on event-driven patterns that act as triggers.

2. CrowdStrike

Inc. (2023). Falcon Platform: Event Data Dictionary. CrowdStrike Falcon Documentation.

Section: "Introduction to Falcon Events"

Reference: This document outlines the various event types (e.g.

ProcessRollup2

DnsRequest

NetworkConnectIP4) that serve as the foundational data source. Custom IOA rules are built by creating logic that triggers on specific values and sequences within these event types.

3. Purdue University. (n.d.). CS 42600: Computer Security

Lecture 19: Intrusion Detection. Purdue University Courseware.

Reference: This course material discusses intrusion detection systems

explaining that modern systems often rely on "behavior-based" or "anomaly-based" detection. This involves defining rules or models of behavior and generating alerts when events deviate or match a malicious pattern

which is the core principle behind CrowdStrike's custom event-based triggers.