You are a Next-Gen SIEM Engineer responsible for parser creation.

The correct answer is C. Assignment Operator .

In Falcon LogScale parser and query syntax, the assignment operator := is used to assign a value to a new field. CrowdStrike’s LogScale documentation explains that := is shorthand for eval, and that it can also be used as shorthand with functions that support an as parameter to assign results to a named output field. This is the right approach when you want to create an ECS field while preserving the existing Vendor field , because you are creating an additional field rather than replacing the original one.

Why the other options are not the best answer:

Regular Expression Field Extraction is used to extract values from raw text when the value is not already parsed, so it is not the normal choice when you already have a Vendor field and simply want to map it to an ECS field as well. As Parameter can name the output field of certain functions, but the CrowdStrike documentation for rename() shows that renaming changes the field name, which does not meet the requirement to keep both field names visible. The rename() examples explicitly state that the original field names are replaced with the new field names.

So for a parser requirement that says “add ECS while maintaining Vendor,” the operationally correct method is to assign the Vendor value into a new ECS field , not rename the Vendor field away.

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