AI-Driven Microsoft 365 Security: Detect, Prioritize and Mitigate Attacks

Rising security risks in Microsoft 365

Why attackers target Microsoft 365

With over 2 million organizations using Microsoft 365 globally, cybercriminals see it as a high-value target for credential theft, account takeovers, data exfiltration, and business email compromise (BEC).

Some of the most common attack methods include:

• Credential theft and account takeovers – Attackers use phishing, brute-force attacks, or password spraying to hijack accounts.
• Business email compromise (BEC) – Cybercriminals gain access to email accounts to impersonate executives and manipulate financial transactions.
• Lateral movement and privilege escalation – Once inside, attackers use compromised credentials to move laterally across an organization’s environment.
• Cloud ransomware and malware – Microsoft 365 can be exploited to deliver ransomware via malicious email attachments or compromised OneDrive links.

Without real-time visibility, behavior-based detection, and automated threat response, organizations struggle to detect and contain these types of attacks effectively.

Why Microsoft 365 security falls short against hybrid, multi-cloud attacks

Cybercriminals move seamlessly across Microsoft 365 (M365), Entra ID, Azure, AWS, Active Directory and Network, stealing credentials of human and non-human identities to execute sophisticated attacks. This grave situation puts sensitive business information at risk, leaving organizations vulnerable and exposed.

Regular security solutions provide basic threat detection but often generate high false positive rates. These tools lack the ability to correlate multiple attack signals, leading to alert fatigue and additional manual effort for security teams. Without advanced AI-driven analytics, they fail to connect the dots across multiple attack stages or prioritize threats effectively. To safeguard your organization and maintain confidence in your operations, it's crucial to adopt a hybrid, multi-cloud security approach that delivers real-time threat detection, automated responses, and comprehensive visibility across M365, network, identity and cloud.

Challenges with traditional solutions include:

• Siloed alerts that lack context – Security teams are bombarded with disconnected alerts that do not provide a complete attack narrative.
• False positives and alert fatigue – Legacy tools overwhelm analysts with excessive notifications, reducing efficiency.
• Slow manual investigations – Security teams waste valuable time correlating data across multiple platforms.
• Limited detection of advanced tactics – Regular solutions often fail to detect modern attacks like living-off-the-land (LotL) techniques

The need for AI-driven threat detection and response to reduce the attack surface in Microsoft 365

Implementing threat detection and response is a critical step in securing Microsoft 365, as it leverages advanced threat detection to quickly identify and respond to potential security incidents.

Key capabilities of AI-driven threat detection and response

• Real-time threat detection – Identifies threats across identity, SaaS, and cloud services in Microsoft 365.
• AI-driven attack AI/ML – Exposes the full attack narrative by correlating security signals across M365, Identity, Cloud and Network.
• Automated threat prioritization – Filters out noise and ranks threats based on actual risk and attack progression.
• Advanced investigation tools – Reduces forensic workload by surfacing attack details in minutes.
• Seamless SOC integration – Connects with SIEM, SOAR, and EDR platforms to automate response actions.

How the Vectra AI Platform helps

AI-driven threat detection and AI/ML

With the Vectra AI Platform for M365, security teams see beyond raw alerts and understand the complete attack story — reducing investigation times from hours to minutes.

• Vectra AI detects living-off-the-land attacks in Microsoft 365, monitoring the full M365 attack surface including Teams, Exchange, OneDrive, eDiscovery, Power Automate and SharePoint, enabling full threat monitoring of business critical data.
• Pre-built AI models detect over 90% of MITRE ATT&CK techniques.
• Real-time threat detection based on behavioral analysis provides deep context on attacker movements

AI threat prioritization and triage

SOC analysts often waste time investigating low-priority alerts, causing delays in responding to real threats. Vectra AI solves this with:

• AI-powered correlation of attack signals to rank threats by urgency score.
• Noise reduction by eliminating false positives.
• Automatic grouping of related incidents, so analysts do not have to piece them together manually.

This helps SOC teams focus on high-risk threats first, making security operations faster and more effective.

Unified visibility across M365, on-premises, and cloud

Unlike regular security tools that provide siloed visibility for each domain, the Vectra AI Platform for M365 provides a unified view of human and non-human identity activities across:

• Microsoft 365 apps (OneDrive, Teams, Exchange, SharePoint)
• Entra ID 
• Active Directory
• Azure Cloud
• AWS Cloud
• On-premises network  environments

This single-pane-of-glass approach ensures that analysts have full visibility across their entire hybrid and multi-cloud security landscape.

Automated incident investigation and response

Security analysts spend too much time on manual investigations. Vectra AI eliminates this by:

• Curating AI-driven insights that answer “who, what, when, and how” behind every attack.
• Reducing mean time to respond (MTTR) by surfacing actionable intelligence in minutes.
• Automating response actions through integrations with SIEM, SOAR, and EDR platforms.

Instead of wasting hours manually analyzing logs, analysts get immediate answers and automated remediation workflows.

Extending cloud detection and response beyond Microsoft 365: protecting Azure and AWS workloads

While securing Microsoft 365 is a priority, many organizations operate in multi-cloud environments where threats extend beyond SaaS applications. Attackers increasingly target AWS and Azure workloads, IAM roles, and cloud-native services, using misconfigurations and stolen credentials to gain unauthorized access. Without real-time visibility and behavioral threat detection, these threats can remain undetected until damage is done.

Key capabilities of Vectra AI Platform for Azure and AWS:

• Continuous cloud and identity threat monitoring – Detects unauthorized access, privilege escalation, and lateral movement across Azure and AWS environments.
• Investigation with zero query – Provides analysts with easy access to relevant AWS and Azure logs and lighted pathways to investigate detections.
• Automated response to cloud attacks – Blocks compromised credentials and executes cloud-native response workflows to lock down cloud principals in real-time.
• AI-powered threat correlation – Connects signals across cloud services to expose multi-stage attack patterns that traditional tools miss.

Organizations leveraging Azure and AWS for critical workloads need proactive detection and intelligent response to stay ahead of emerging threats. Discover how Vectra AI threat detection and response for AWS and Azure provides behavior-based security, automated threat mitigation, and deep visibility into multi-cloud attacks—without slowing down your cloud operations.

To see how Vectra AI can strengthen your Microsoft 365 security strategy, see Vectra AI in action and experience AI-driven detection and response.