Welcome to this post on harnessing the power of Security Information and Event Management (SIEM) tools in searching for security events. Today, we’re going to explore the varied search methodologies used by leading SIEM tools like Splunk and Chronicle, essential for any security analyst striving to uncover and address security events effectively.

The Art of Searching in Splunk

Splunk, a prominent SIEM tool, employs its unique querying language, Search Processing Language (SPL). This powerful language allows you to craft intricate searches and retrieve specific events from indexes.

For instance, let’s consider a basic SPL search for identifying failed events:

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index=main fail

This command prompts Splunk to search within the ‘main’ index for events containing the term “fail.” Utilising SPL effectively can significantly reduce the time needed to obtain precise results from various data sources.

The Versatility of Pipes in SPL

Similar to piping in Linux bash shell, SPL uses the pipe character | to chain commands together. This functionality is pivotal in refining data to obtain precise results. For example:

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index=main fail | chart count by host

This command chain first searches for failed events and then generates a chart based on the count of these events by host. Such an approach is invaluable in identifying patterns like excessive failure counts from specific hosts.

Expanding Searches with Wildcards

Wildcards in Splunk, symbolized by an asterisk *, are used to expand search terms. For example, fail* in a search would include variations like “failed” or “failure.” This flexibility is crucial in broadening the scope of your searches to include similar but not identical data patterns.

Chronicle’s Approach to Event Searches

Chronicle, another SIEM giant, offers two main types of searches: Unified Data Model (UDM) Search and Raw Log Search.

• Unified Data Model (UDM) Search: This default search type sifts through indexed, structured data normalised in UDM. UDM searches are faster and more efficient, especially for structured queries. For example, a simple UDM search might look like:Copy codemetadata.event_type = “USER_LOGIN” This command searches for events related to user logins, utilising Chronicle’s UDM fields.
• Raw Log Search: When detailed or unstructured information is needed, Raw Log Search delves into the raw, unparsed logs. Although slower, it’s incredibly thorough, supporting regular expressions for pattern matching. A Raw Log Search might be employed when seeking specific details not available in normalized data, like unique usernames or file hashes.

Key Takeaways

Understanding the varied search capabilities of SIEM tools like Splunk and Chronicle is crucial for any security analyst. These tools, each with their unique approaches, empower you to delve deep into data, supporting the detection and rapid response to security incidents.

For those keen to expand their expertise, Splunk’s Search Manual and Chronicle’s quickstart guide are invaluable resources. These guides offer a deeper dive into their respective search languages and methodologies, equipping you with the knowledge to conduct efficient and effective security investigations.

In summary, mastering these search methods in SIEM tools is not just about finding data; it’s about uncovering the story behind the data, a critical skill in the fast-paced world of cybersecurity. Happy searching!