Microsoft Sentinel and XDR: From Detection to Action 

A Security Operations Centre (SOC) needs more than a steady stream of alerts. It needs reliable data, useful detections and clear response processes. Analysts also need the context and authority to act quickly. 

Microsoft Sentinel, formerly Azure Sentinel, provides a cloud-native security information and event management platform. It collects and analyses security data across Microsoft, multicloud, on-premises and third-party environments. 

However, detecting a threat is only the beginning. The real test is whether your SOC can contain it before the damage spreads. 

Extended detection and response (XDR) connects activity across endpoints, identities, email, applications and cloud workloads. Combined with Sentinel and an effective SOC, it turns isolated alerts into coordinated action. 

What is Microsoft Sentinel? 

Microsoft Sentinel is Microsoft’s cloud-native security information and event management (SIEM) platform. It also provides security orchestration, automation and response (SOAR) capabilities. 

The SIEM function collects events and alerts from across your environment. It then correlates those signals to identify suspicious activity. The SOAR function helps teams automate repeatable investigation and response tasks. 

Together, these capabilities help a SOC: 

• Collect and normalise security telemetry.  

• Detect suspicious behaviour and known attack patterns.  

• Group related alerts into incidents.  

• Investigate users, devices, IP addresses and cloud resources.  

• Hunt proactively with Kusto Query Language.  

• Automate investigation and response workflows.  

• Build operational and executive reporting.  

Microsoft now delivers Sentinel through its unified security operations experience in the Microsoft Defender portal. This brings SIEM and XDR signals into a shared incident queue. Analysts can investigate connected activity without moving constantly between different consoles. 

Many teams still refer to the platform as Azure Sentinel. However, current Microsoft documentation and product interfaces use Microsoft Sentinel. 

How Microsoft Sentinel and XDR work together 

Microsoft Sentinel and Defender XDR perform different but complementary roles. 

Sentinel provides broad visibility across the organisation. It can ingest security data from Microsoft products, third-party tools, infrastructure and custom applications. This makes it useful for centralised monitoring, compliance reporting and cross-environment detection. 

Defender XDR connects signals from Microsoft security controls. It correlates activity across endpoints, identities, email, applications and cloud services. This helps analysts understand how an attack entered and moved through the environment. 

For example, Sentinel might detect an unusual sign-in followed by a privilege change. Defender XDR could add suspicious endpoint activity, email evidence and identity risk to the same investigation. 

Together, those signals help the SOC answer three important questions: 

1. What happened?  

2. What does it affect?  

3. What action should we take?  

The third question matters most. Visibility without an effective response process can leave an organisation watching an attack unfold. 

A mature XDR capability connects detection to containment. When analysts confirm a high-confidence threat, they can take agreed actions to limit its impact. 

Key Microsoft Sentinel capabilities 

Sentinel offers a wide range of features. However, five capabilities provide much of its operational value. 

Data collection and normalisation 

Connectors bring logs and alerts into Sentinel from Microsoft and third-party platforms. Sources may include identities, endpoints, applications, firewalls, cloud services and network devices. 

Sentinel also supports interfaces such as Syslog, Common Event Format and APIs. Its data models help normalise different sources into consistent schemas. 

However, collecting more data does not always improve security. Every source should support a defined detection, investigation, compliance or response use case. 

Analytics and incident correlation 

Analytics rules identify activity that may indicate a threat. Teams can use Microsoft templates, adapt existing rules or write custom queries. 

Useful detections connect technical activity to realistic attack paths. An unusual sign-in, privilege change and suspicious endpoint process may appear minor separately. Together, they could indicate account compromise. 

Sentinel can group related signals into incidents. Defender XDR adds context from connected Microsoft security controls. Analysts can then investigate the wider attack instead of assessing each alert in isolation. 

Threat hunting and investigation 

Threat hunting allows analysts to search for suspicious patterns before an alert confirms an incident. Queries can examine identity, endpoint, network and cloud data. 

Workbooks, entity pages and incident graphs show trends and relationships between accounts, devices, IP addresses and resources. 

Hunting works best when analysts begin with a testable question. For example, has a compromised account created new credentials or accessed an unusual application? A focused question produces more value than searching every available log. 

Automation and remediation 

Sentinel automation rules and playbooks reduce repetitive work. Playbooks use Azure Logic Apps to connect Sentinel with other systems and perform defined tasks. 

A basic workflow might enrich an incident, create a service ticket and notify the on-call team. A mature workflow can also initiate a containment action. 

Depending on the incident and approved playbooks, response actions may include: 

• Isolating a compromised endpoint.  

• Disabling a compromised identity.  

• Blocking a malicious indicator.  

• Starting an automated investigation.  

• Escalating an incident for approval.  

• Preserving evidence for further analysis.  

Teams can run these workflows automatically or after analyst approval. Start with low-risk, reversible actions. Then introduce stronger controls once the team has tested the workflow. 

Threat intelligence and security content 

Threat intelligence gives analysts more context about indicators, techniques and active campaigns. Sentinel can use Microsoft intelligence and supported external sources during detection and investigation. 

The Content Hub also provides packaged connectors, analytics rules, hunting queries, workbooks and playbooks. 

This content can speed deployment. However, teams should review and tune each item before enabling it. A template cannot account for every organisation’s systems, users and risks. 

Why detection without remediation falls short 

Some security services stop after raising an alert. The customer receives a notification, reviews the evidence and decides what to do next. 

That model may work when an internal team has enough people and expertise. However, it can introduce delays during a fast-moving incident. 

Consider a compromised identity detected outside business hours. The alert may be accurate and detailed. Yet the attacker can continue operating until someone reviews the notification and disables the account. 

A managed XDR service should not stop at saying something happened. It should help do something about it. 

Macquarie Cloud Services’ managed XDR service combines Microsoft Sentinel, Defender XDR, automation and a 24×7 Australian SOC. When analysts identify a high-confidence threat, they can help contain it according to agreed playbooks and response authority. 

The exact action depends on the incident and operating model. Not every alert should trigger automatic containment. Poorly controlled automation could interrupt legitimate work or affect a critical service. 

Instead, the SOC should combine high-confidence detection with business context and defined approval thresholds. This supports faster containment without removing human judgement. 

How to improve Sentinel detection and response 

Installing connectors and enabling rules will not automatically create a mature SOC. Organisations need a continuous process for improving detection and response. 

Start with priority risks 

Identify the threats and business processes that matter most. Identity compromise, ransomware, data theft and privileged access misuse are common priorities. 

For each use case, define: 

• The data needed to detect the activity.  

• The detection logic and investigation steps.  

• The containment or remediation action.  

• Who can authorise that action.  

• When the SOC can act immediately.  

This approach prevents indiscriminate data ingestion and gives the SOC a clear way to measure coverage. 

Monitor data and detection quality 

A detection cannot work when its data source stops sending information. Monitor connector health, ingestion delays, parsing failures and unexpected volume changes. 

Review false positives, duplicate alerts and incidents closed without action. Then adjust thresholds, entity mapping, suppression and detection logic. 

Do not judge quality by alert volume alone. Instead, ask whether each detection addresses a relevant threat and provides enough evidence for action. 

Test response playbooks 

Document investigation steps, response authority and escalation paths. Specify which actions analysts can take immediately and which need customer approval. 

Test those procedures through tabletop exercises and controlled simulations. Confirm that the technology works and the right people receive timely updates. 

After an exercise or incident, update the detections, automation and playbooks. This creates a cycle of continuous improvement. 

Measure containment, not only notification 

Mean time to detect and mean time to respond remain useful metrics. However, they do not show whether the SOC actually reduced the threat. 

Also measure: 

• Time from detection to containment.  

• Automation success and failure rates.  

• Incidents that needed manual escalation.  

• Repeat incidents involving the same weakness.  

• Time between containment and recovery.  

• Coverage of high-priority threats.  

These measures show whether the SOC is producing security outcomes rather than processing alerts. 

When managed XDR makes sense 

Microsoft Sentinel reduces much of the infrastructure burden associated with traditional SIEM platforms. It does not remove the need for 24×7 monitoring, detection engineering and incident response expertise. 

Managed XDR can help organisations that lack the people, coverage or time to operate Sentinel continuously. It can also extend an internal security team that needs stronger Defender governance and faster containment. 

Before choosing a provider, ask: 

• Who monitors the environment, and from where?  

• How does the team tune detections for our risks?  

• How are Sentinel and Defender XDR signals correlated?  

• What happens after an incident is confirmed?  

• Which actions can analysts take without approval?  

• How are response playbooks tested?  

• How are outcomes reported?  

• Who owns the rules, playbooks and data?  

These questions separate alert monitoring from genuine response capability. A provider should explain both how it detects threats and what it will do once it finds one. 

Move from detection to action 

Microsoft Sentinel gives your SOC broad visibility, stronger correlation and faster investigation. XDR extends that value by connecting activity across identities, endpoints, applications and cloud services. 

However, the strongest security outcome comes from linking those capabilities to action. 

Macquarie Cloud Services combines Microsoft Sentinel and Defender XDR with a 24×7 Australian SOC. The focus is not simply on notifying you about a threat. It is on helping investigate, contain and remediate it before the impact grows. 

Talk to Macquarie Cloud Services about managed XDR and strengthen the path from detection to action.