Splunk to Microsoft Sentinel Migration

Microsoft Sentinel is a cloud-native SIEM (Security Information and Event Management) and SOAR (Security Orchestration, Automation, and Response) solution built on Microsoft Azure. It collects security signals from users, devices, applications, and infrastructure — across on-premises environments, Azure, and other cloud providers — and uses AI and machine learning to detect threats, support incident investigation, and enable automated response.

As an Azure-native service, Sentinel integrates directly with Microsoft 365, Microsoft Defender, Azure Active Directory, and the broader Microsoft security product family. Organizations choosing to migrate from Splunk to Microsoft Sentinel often do so as part of a wider Microsoft security consolidation. Crest Data’s migration service handles the full transition, converting Splunk detection rules, dashboards, and workflows into their Sentinel equivalents.

Yes — Microsoft Sentinel is a full SIEM and SOAR solution. As a SIEM, it ingests and correlates security data from across your environment, detects threats using built-in and custom analytics rules (authored in KQL — Kusto Query Language), and surfaces security incidents for SOC investigation. As a SOAR tool, Sentinel supports automated playbooks built on Azure Logic Apps, which can trigger automated responses to security events — such as isolating a compromised device, enriching an incident with threat intelligence, or creating a ticket in your ITSM system.

For organizations migrating their SIEM operations from Splunk Enterprise Security to Microsoft Sentinel, Crest Data maps Splunk ES content — detection rules, correlation searches, notable event workflows, and dashboards — into the equivalent Sentinel analytics rules, workbooks, and automation playbooks.

Microsoft Sentinel is priced based on the volume of data ingested and analysed. Two pricing models are available:

• Pay-As-You-Go — billed per GB of data analyzed, with no upfront commitment.
• Commitment Tiers — discounted daily rates for organizations committing to a fixed data ingestion volume (available from 100GB/day upward).

Microsoft also provides a Microsoft Sentinel benefit for Microsoft 365 E5 customers, which includes free data ingestion for logs originating from Microsoft 365 services — up to 5MB per user per day. This benefit can meaningfully reduce total Sentinel costs for organizations already on the E5 licensing tier.

Crest Data includes a detailed Sentinel cost modelling exercise as part of every Splunk to Sentinel migration scoping engagement, helping you accurately forecast your post-migration spend.

Microsoft Sentinel is not included as a bundled service within the Microsoft 365 E5 license — it is a separately billed Azure service. However, Microsoft 365 E5 customers do receive a Sentinel data benefit: free data ingestion of up to 5MB per user per day for logs originating from Microsoft 365 data connectors, including Azure Active Directory, Microsoft Defender for Endpoint, Defender for Office 365, and other Microsoft 365 security signals.

For organizations with large Microsoft 365 E5 deployments, this benefit can cover a substantial portion of their daily Sentinel data volume at no additional cost. Understanding this benefit — and how it applies to your specific data sources — is an important part of the migration business case. Crest Data’s pre-migration assessment includes a full review of your Microsoft licensing position and its impact on projected Sentinel costs.

Yes — Crest Data’s migration engine automates the conversion of Splunk content into Microsoft Sentinel. This includes:

• SPL to KQL translation — Splunk detection rules, correlation searches, and saved searches are converted to Sentinel Analytics Rules authored in KQL (Kusto Query Language).
• Dashboards to Workbooks — Splunk dashboards are recreated as Microsoft Sentinel Workbooks, maintaining the same visualizations and data views.
• Alerts to Analytics Rules — Splunk alert configurations are mapped to Sentinel Analytics Rule thresholds and scheduling.
• Lookup tables to Watchlists — Splunk lookup tables are converted to Sentinel Watchlists for use in detection and investigation workflows.

Each migration is accompanied by a detailed asset report showing conversion outcomes and flagging any items requiring specialist review. Our certified Sentinel engineers handle all complex SPL-to-KQL cases that automated conversion cannot fully resolve.