CrowdStrike CCFH-202b - CrowdStrike Certified Falcon Hunter

In Detection Analysis , the process w3wp.exe is a critical focal point as it is the IIS (Internet Information Services) Worker Process. Under normal operating conditions, w3wp.exe should be handling web requests and should almost never spawn interactive shells like powershell.exe or cmd.exe. When a process tree shows a web worker process spawning a shell, it is a high-confidence Indicator of Attack (IOA) typically associated with a Web Shell or a successful exploitation of a web application vulnerability.

The subsequent commands—whoami.exe and net1.exe—are classic post-exploitation Reconnaissance tools. whoami is used by an attacker to determine the privileges of the service account they have compromised, while net1 is used to enumerate local or domain users and groups to identify potential targets for lateral movement. The progression from a web process to a shell and then to identity/network discovery is a definitive behavioral pattern of a remote attacker establishing a foothold and performing initial situational awareness. While an administrator might use these tools for troubleshooting (Option B), they would typically do so via a direct login or a remote management session, not through the w3wp.exe parent tree. Recognizing this specific lineage is essential for hunters to differentiate between legitimate administrative maintenance and an active, live-site compromise requiring immediate intervention and containment.

In the CrowdStrike Query Language (CQL) used within the LogScale-powered Advanced Event Search, the groupBy() function is the essential tool for data aggregation and summarization. As observed in the first image, Line 2 of the query (partially obscured) utilizes the function= parameter to define multiple aggregate calculations, such as count(aid, distinct=true) and count(aid). This syntax is the hallmark of a groupBy statement.

The results shown in the subsequent images display a table where each row is unique to a specific SHA256HashData . This indicates that the data has been grouped by that specific field to provide a summary of its activity across the environment. The groupBy function allows a hunter to take millions of individual process events and collapse them into a readable format that highlights uniqueEndpoints and totalExecutions per file hash.

This methodology is fundamental to Hunting Analytics , specifically for performing Least Frequency Analysis . By grouping by the hash and counting the unique endpoints, an analyst can quickly identify binaries that are running on only one or two systems—a common characteristic of targeted malware or custom hacking tools. While functions like table (Option C) are used to format the final display and eval (Option A) is used for field transformations, only groupBy provides the structural aggregation required to generate the multi-column statistical overview seen in the results.