Auto-Analyzing LS_ISAC Emails Using Security Copilot

Introduction

Cyber threat intelligence sharing is a crucial aspect of modern security operations. The Legal Services Information Sharing and Analysis Center (LS-ISAC) provides threat intelligence to legal firms through email-based alerts. Manually analyzing these emails is inefficient and time-consuming. Microsoft Security Copilot, powered by GPT-4, can automate the process, providing structured insights with minimal human intervention.

This blog post outlines a step-by-step guide to automating the analysis of LS-ISAC emails using Microsoft Security Copilot, Microsoft Defender, and Sentinel.

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Solution Overview

We will set up an automated pipeline where:

• LS-ISAC threat intelligence emails are ingested.

• Microsoft Security Copilot extracts relevant details.

• The threat intelligence is correlated with security events in Microsoft Sentinel.

• Security teams receive actionable alerts with recommended mitigations.

Flow Diagram

+------------------+      +--------------------+      +----------------------+
| LS-ISAC Email   | ---> | Security Copilot  | ---> | Microsoft Sentinel   |
| (Threat Intel)  |      | (AI Processing)   |      | (Threat Correlation) |
+------------------+      +--------------------+      +----------------------+
         |                         |                          |
         |                         |                          |
         v                         v                          v
+------------------+      +---------------------+      +---------------------+
| Defender for     | ---> | Threat Intelligence | ---> | SOC Alerting       |
| Office 365       |      | (Automated Report)  |      | (Remediation)       |
+------------------+      +---------------------+      +---------------------+

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Step-by-Step Implementation

Step 1: Ingest LS-ISAC Emails into Microsoft 365 Defender

1. Configure Email Rules

   • Create a rule in Exchange Online to detect LS-ISAC emails.

   • Apply a transport rule to tag these emails with a specific label.

2. Forward Emails to Microsoft Sentinel

   • Enable Microsoft Defender for Office 365 to scan LS-ISAC emails.

   • Use Microsoft Sentinel Email Ingestion API to store the emails in a dedicated threat intelligence table.

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Step 2: Extract and Parse Email Content using Security Copilot

1. Deploy Security Copilot in Defender

   • Navigate to Microsoft 365 Defender > Settings > Security Copilot.

   • Enable AI-assisted threat analysis.

2. Create an Automated Playbook

   • Go to Microsoft Sentinel > Playbooks.

   • Create a Logic App that triggers when an LS-ISAC email is received.

   • Use Security Copilot API to extract and analyze key indicators (e.g., IoCs, malware signatures, URLs, TTPs).

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Step 3: Correlate with Threat Intelligence in Sentinel

1. Extract Threat Intelligence Indicators

   • Parse extracted IoCs into a structured format (IP addresses, domains, hashes).

   • Enrich IoCs with Threat Intelligence Platforms (TIPs) like VirusTotal, AlienVault, or Microsoft Threat Intelligence.

2. Correlate with Security Logs

   • Use Kusto Query Language (KQL) in Microsoft Sentinel to check if any IoCs match recent security events.

   • Example KQL query:

let IoCs = externaldata(IoC:string) ["https://storage.blob.core.windows.net/ioc-list.csv"];
SecurityEvent
| where TimeGenerated > ago(7d)
| where IpAddress in (IoCs) or FileHash in (IoCs)

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Step 4: Automate Alerting and Mitigation

1. Generate Security Alerts

   • If IoCs match existing threats, create an Incident in Microsoft Sentinel.

   • Attach AI-generated insights from Security Copilot to the alert.

2. Automate Response Actions

   • Use Microsoft Defender XDR to block malicious domains/IPs.

   • Automate response via Sentinel SOAR Playbooks.

   • Example: Trigger an Azure Logic App to isolate infected devices.

3. Notify Security Teams

   • Send an automated Teams/Email alert with:

     • Extracted threat intelligence details.

     • Affected assets.

     • Suggested mitigations.

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Conclusion

Automating the analysis of LS-ISAC emails using Microsoft Security Copilot significantly enhances threat intelligence workflows. This approach enables organizations to:

• Rapidly process threat intelligence.

• Automate correlation with security events.

• Improve incident response times.

By leveraging Microsoft Defender, Sentinel, and SOAR Playbooks, security teams can effectively mitigate threats before they impact the organization.