Electronic Discovery Reference Model en Microsoft 365

Electronic Discovery Reference Model in Microsoft 365

May 26, 2025 Juan Antonio Calles

Digital forensic analysis has drastically evolved with the widespread adoption of cloud environments, especially in organizations using Microsoft 365. Compared to the traditional method, based on downloading and locally analyzing files in formats like PST, today we have native tools that allow preserving, analyzing, and documenting electronic evidence directly in the cloud, with greater legal and technical guarantees. In this context, Microsoft Purview eDiscovery (Premium) stands out as a key platform, aligned with the international reference model EDRM (Electronic Discovery Reference Model).

EDRM provides a widely accepted regulatory framework to manage digital evidence in a structured way during audits, litigation, or internal investigations. This model defines nine key phases that ensure traceability and validity of electronic information: Information Governance, Identification, Preservation, Collection, Processing, Review, Analysis, Production, and Presentation.

Microsoft has integrated these stages within its Purview eDiscovery solution, allowing legal teams and forensic experts to execute the entire investigation lifecycle without leaving the Microsoft 365 environment. This integration reduces risks, keeps the chain of custody intact, and provides thorough traceability.

Step-by-Step Forensic Investigation

1. Case Creation and Custodian Identification

It all starts with opening a "case" in Purview, a logical unit that groups related activities, evidence, and users. Next, custodians are identified, that is, employees whose communications or files must be analyzed.

2. Legal Hold: Activating "Legal Hold"

With "Legal Hold", custodian data is frozen in its original state, preventing modification or deletion, even if the user attempts to alter the content. This action is automatically documented, ensuring traceability.

3. Intelligent Data Collection

eDiscovery allows the use of advanced filters and KQL language to select relevant information based on keywords, dates, senders, or specific patterns.

4. Processing and deduplication

Purview Premium offers advanced features to reduce data volume through deduplication, thus facilitating subsequent analysis.

5. Legal review and forensic analysis

Data can be tagged, filtered, and analyzed with tools like email threading and entity analysis to identify key relationships.

6. Export and documentation

Evidence is exported in formats such as PST or EML, with an integrity manifest (hashes, metadata, logs) that guarantees the chain of custody.

7. Presentation in court or audit

Purview facilitates technical and legal reports that can be used as evidence in court, reinforcing their probative value.

Licensing

What are the differences between eDiscovery Standard and Premium?

eDiscovery (Standard): More oriented to basic investigations. Includes searches, legal hold, and limited export.
eDiscovery (Premium): Includes mass processing, advanced review, intelligent analysis, and legal workflow control.

With Purview, there is no need to export for analysis: everything happens in a secure and traced architecture, without compromising the integrity of the evidence. Microsoft acts as a trusted third party, ensuring that data remains intact until its formal export.

Conclusion

Microsoft Purview eDiscovery (Premium) represents a paradigm shift in cloud forensic analysis. Thanks to its alignment with the EDRM model, it allows working with technical efficiency and legal robustness. For digital experts and regulated organizations, this tool has become an essential standard.

If you want to learn more about the topic, I recommend my new book (free), Forensic Analysis of Emails in Office 365, which you can download from this link.

Greetings!

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