Addressing the OWASP Top 10 Risks in Agentic AI with Microsoft Copilot Studio

Agentic AI is moving fast from pilots to production. That shift changes the security conversation. These systems do not just generate content. They can retrieve sensitive data, invoke tools, and take action using real identities and permissions. When something goes wrong, the failure is not limit...

Addressing the OWASP Top 10 Risks in Agentic AI with Microsoft Copilot Studio

Agentic AI is moving fast from pilots to production. That shift changes the security conversation. These systems do not just generate content. They can retrieve sensitive data, invoke tools, and take action using real identities and permissions. When something goes wrong, the failure is not limit...

How Microsoft Defender protects high-value assets in real-world attack scenarios

In this article 1. Using asset context to strengthen detection 2. How high-value asset protection works 3. Real-world high-value asset protection scenarios 4. Protecting your HVAs 5. Learn more High-value assets including domain controllers, web servers, and identity infrastructure are frequent...

Identity security is the new pressure point for modern cyberattacks

Identity attacks no longer hinge on who a cyberattacker compromises, but on what that identity can access. As organizations manage growing numbers of human, non-human, and agentic identities, their access fabric multiplies across apps, resources, and environments, which increases both operational...

Identity security is the new pressure point for modern cyberattacks

Identity attacks no longer hinge on who a cyberattacker compromises, but on what that identity can access. As organizations manage growing numbers of human, non-human, and agentic identities, their access fabric multiplies across apps, resources, and environments, which increases both operational...

Guidance for detecting, investigating, and defending against the Trivy supply chain compromise

In this article 1. Analyzing the Trivy supply chain compromise 2. Detection and investigation 3. Mitigation and protection guidance 4. Advanced hunting queries 5. References 6. Learn more On March 19, 2026, Trivy, Aqua Security’s widely used open-source vulnerability scanner, was reported to have...

Guidance for detecting, investigating, and defending against the Trivy supply chain compromise

In this article 1. Analyzing the Trivy supply chain compromise 2. Detection and investigation 3. Mitigation and protection guidance 4. Advanced hunting queries 5. References 6. Learn more On March 19, 2026, Trivy, Aqua Security’s widely used open-source vulnerability scanner, was reported to have...

Governing AI agent behavior: Aligning user, developer, role, and organizational intent

AI agents increasingly perform tasks that involve reasoning, acting, and interacting with other systems. Building a trusted agent requires ensuring it operates within the correct boundaries and performs tasks consistent with its intended purpose. In practice, this requires aligning several layers...

Case study: How predictive shielding in Defender stopped GPO-based ransomware before it started

In this article 1. The growing threat: GPO abuse in ransomware operations 2. The incident 3. The results 4. The hardening dilemma: Why threat actors love operational mechanisms 5. Predictive shielding: Contextual, just-in-time hardening 6. Closing the gap 7. References Summary Microsoft Defender...

Case study: How predictive shielding in Defender stopped GPO-based ransomware before it started

In this article 1. The growing threat: GPO abuse in ransomware operations 2. The incident 3. The results 4. The hardening dilemma: Why threat actors love operational mechanisms 5. Predictive shielding: Contextual, just-in-time hardening 6. Closing the gap 7. References Summary Microsoft Defender...

CTI-REALM: A new benchmark for end-to-end detection rule generation with AI agents

Excerpt: CTI-REALM is Microsoft’s open-source benchmark for evaluating AI agents on real-world detection engineering—turning cyber threat intelligence CTI into validated detections. Instead of measuring “CTI trivia,” CTI-REALM tests end-to-end workflows: reading threat reports, exploring telemetr...

Secure agentic AI end-to-end

Next week, RSAC™ Conference celebrates its 35-year anniversary as a forum that brings the security community together to address new challenges and embrace opportunities in our quest to make the world a safer place for all. As we look towards that milestone, agentic AI is reshaping industries...

Secure agentic AI end-to-end

Next week, RSAC™ Conference celebrates its 35-year anniversary as a forum that brings the security community together to address new challenges and embrace opportunities in our quest to make the world a safer place for all. As we look towards that milestone, agentic AI is reshaping industries...

New tools and guidance: Announcing Zero Trust for AI

Over the past year, I have had conversations with security leaders across a variety of disciplines, and the energy around AI is undeniable. Organizations are moving fast, and security teams are rising to meet the moment. Time and again, the question comes back to the same thing: "We're adopting A...

When tax season becomes cyberattack season: Phishing and malware campaigns using tax-related lures

In this article 1. A wide range of tax-themed campaigns 2. How to protect users and organization against tax-themed campaigns 3. Microsoft Defender detection and hunting guidance 4. Indicators of compromise During tax season, threat actors reliably take advantage of the urgency and familiarity of...

When tax season becomes cyberattack season: Phishing and malware campaigns using tax-related lures

In this article 1. A wide range of tax-themed campaigns 2. How to protect users and organization against tax-themed campaigns 3. Microsoft Defender detection and hunting guidance 4. Indicators of compromise During tax season, threat actors reliably take advantage of the urgency and familiarity of...

Observability for AI Systems: Strengthening visibility for proactive risk detection

Adoption of Generative AI GenAI and agentic AI has accelerated from experimentation into real enterprise deployments. What began with copilots and chat interfaces has quickly evolved into powerful business systems that autonomously interact with sensitive data, call external APIs, connect to...

Observability for AI Systems: Strengthening visibility for proactive risk detection

Adoption of Generative AI GenAI and agentic AI has accelerated from experimentation into real enterprise deployments. What began with copilots and chat interfaces has quickly evolved into powerful business systems that autonomously interact with sensitive data, call external APIs, connect to...

New Microsoft Purview innovations for Fabric to safely accelerate your AI transformation

As organizations adopt AI, security and governance remain core primitives for safe AI transformation and acceleration. After all, data leaders are aware of the notion that: Your AI is only as good as your data. Organizations are skeptical about AI transformation due to concerns of sensitive data...

New Microsoft Purview innovations for Fabric to safely accelerate your AI transformation

As organizations adopt AI, security and governance remain core primitives for safe AI transformation and acceleration. After all, data leaders are aware of the notion that: Your AI is only as good as your data. Organizations are skeptical about AI transformation due to concerns of sensitive data...

Help on the line: How a Microsoft Teams support call led to compromise

In our eighth Cyberattack Series report, Microsoft Incident Response—the Detection and Response Team DART—investigates a recent identity-first, human-operated intrusion that relied less on exploiting software vulnerabilities and more on deception and legitimate tools. After a customer reached out...

Help on the line: How a Microsoft Teams support call led to compromise

In our eighth Cyberattack Series report, Microsoft Incident Response—the Detection and Response Team DART—investigates a recent identity-first, human-operated intrusion that relied less on exploiting software vulnerabilities and more on deception and legitimate tools. After a customer reached out...

Storm-2561 uses SEO poisoning to distribute fake VPN clients for credential theft

In this article 1. From search to stolen credentials: Storm-2561 attack chain 2. Defending against credential theft campaigns 3. Microsoft Defender detection and hunting guidance 4. Indicators of compromise In mid-January 2026, Microsoft Defender Experts identified a credential theft campaign tha...

Storm-2561 uses SEO poisoning to distribute fake VPN clients for credential theft

In this article 1. From search to stolen credentials: Storm-2561 attack chain 2. Defending against credential theft campaigns 3. Microsoft Defender detection and hunting guidance 4. Indicators of compromise In mid-January 2026, Microsoft Defender Experts identified a credential theft campaign tha...

From transparency to action: What the latest Microsoft email security benchmark reveals

In our last benchmarking post, Clarity in complexity: New insights for transparent email security ,1 we shared why transparency matters more than ever in email security and how clear, consistent benchmarking helps security teams cut through noise and make confident decisions. Today, we’re...

From transparency to action: What the latest Microsoft email security benchmark reveals

In our last benchmarking post, Clarity in complexity: New insights for transparent email security ,1 we shared why transparency matters more than ever in email security and how clear, consistent benchmarking helps security teams cut through noise and make confident decisions. Today, we’re...

Detecting and analyzing prompt abuse in AI tools

This second post in our AI Application Security series is all about moving from planning to practice. AI Application Series 1: Security considerations when adopting AI tools established how AI adoption expands the attack surface and our threat-modelling guidance on the Microsoft security blog...

Detecting and analyzing prompt abuse in AI tools

This second post in our AI Application Security series is all about moving from planning to practice. AI Application Series 1: Security considerations when adopting AI tools established how AI adoption expands the attack surface and our threat-modelling guidance on the Microsoft security blog...

Contagious Interview: Malware delivered through fake developer job interviews

Microsoft Defender Experts has observed the Contagious Interview campaign, a sophisticated social engineering operation active since at least December 2022. Microsoft continues to detect activity associated with this campaign in recent customer environments, targeting software developers at...

Contagious Interview: Malware delivered through fake developer job interviews

Microsoft Defender Experts has observed the Contagious Interview campaign, a sophisticated social engineering operation active since at least December 2022. Microsoft continues to detect activity associated with this campaign in recent customer environments, targeting software developers at...

Secure agentic AI for your Frontier Transformation

Today we shared the next step to make Frontier Transformation real for customers across every industry with Wave 3 of Microsoft 365 Copilot, Microsoft Agent 365, and Microsoft 365 E7: The Frontier Suite. Introducing the First Frontier Suite built on Intelligence and Trust As our customers rapidly...

Secure agentic AI for your Frontier Transformation

Today we shared the next step to make Frontier Transformation real for customers across every industry with Wave 3 of Microsoft 365 Copilot, Microsoft Agent 365, and Microsoft 365 E7: The Frontier Suite. Introducing the First Frontier Suite built on Intelligence and Trust As our customers rapidly...

AI as tradecraft: How threat actors operationalize AI

In this article 1. AI as an enabler for cyberattacks 2. Post-compromise misuse of AI 3. Emerging trends 4. Mitigation guidance for AI-enabled threats 5. Microsoft Defender detections Threat actors are operationalizing AI along the cyberattack lifecycle to accelerate tradecraft, abusing both...

AI as tradecraft: How threat actors operationalize AI

In this article 1. AI as an enabler for cyberattacks 2. Post-compromise misuse of AI 3. Emerging trends 4. Mitigation guidance for AI-enabled threats 5. Microsoft Defender detections Threat actors are operationalizing AI along the cyberattack lifecycle to accelerate tradecraft, abusing both...

Women’s History Month: Encouraging women in cybersecurity at every career stage

Women’s History Month—and International Women’s Day on March 8, 2026—always gives me pause for reflection. It’s a moment to think about how far we’ve come and think about who we choose to uplift as we look ahead. Throughout my career, I’ve been inspired by extraordinary women leaders—trailblazers...

Malicious AI Assistant Extensions Harvest LLM Chat Histories

Microsoft Defender has been investigating reports of malicious Chromium‑based browser extensions that impersonate legitimate AI assistant tools to harvest LLM chat histories and browsing data. Reporting indicates these extensions have reached approximately 900,000 installs. Microsoft Defender...

Malicious AI Assistant Extensions Harvest LLM Chat Histories

Microsoft Defender has been investigating reports of malicious Chromium‑based browser extensions that impersonate legitimate AI assistant tools to harvest LLM chat histories and browsing data. Reporting indicates these extensions have reached approximately 900,000 installs. Microsoft Defender...

Inside Tycoon2FA: How a leading AiTM phishing kit operated at scale

In this article 1. Operational overview of Tycoon2FA 2. Mitigation and protection guidance 3. Microsoft Defender detections Following its emergence in August 2023, Tycoon2FA rapidly became one of the most widespread phishing-as-a-service PhaaS platforms, enabling campaigns responsible for tens of...

Inside Tycoon2FA: How a leading AiTM phishing kit operated at scale

In this article 1. Operational overview of Tycoon2FA 2. Mitigation and protection guidance 3. Microsoft Defender detections Following its emergence in August 2023, Tycoon2FA rapidly became one of the most widespread phishing-as-a-service PhaaS platforms, enabling campaigns responsible for tens of...

Signed malware impersonating workplace apps deploys RMM backdoors

In February 2026, Microsoft Defender Experts identified multiple phishing campaigns attributed to an unknown threat actor. The campaigns used workplace meeting lures, PDF attachments, and abuse of legitimate binaries to deliver signed malware. Phishing emails directed users to download malicious...

Signed malware impersonating workplace apps deploys RMM backdoors

In February 2026, Microsoft Defender Experts identified multiple phishing campaigns attributed to an unknown threat actor. The campaigns used workplace meeting lures, PDF attachments, and abuse of legitimate binaries to deliver signed malware. Phishing emails directed users to download malicious...

OAuth redirection abuse enables phishing and malware delivery

Microsoft observed phishing-led exploitation of OAuth’s by-design redirection mechanisms. The activity targets government and public-sector organizations and uses silent OAuth authentication flows and intentionally invalid scopes to redirect victims to attacker-controlled infrastructure without...

OAuth redirection abuse enables phishing and malware delivery

Microsoft observed phishing-led exploitation of OAuth’s by-design redirection mechanisms. The activity targets government and public-sector organizations and uses silent OAuth authentication flows and intentionally invalid scopes to redirect victims to attacker-controlled infrastructure without...

Threat modeling AI applications

Proactively identifying, assessing, and addressing risk in AI systems We cannot anticipate every misuse or emergent behavior in AI systems. We can , however, identify what can go wrong, assess how bad it could be, and design systems that help reduce the likelihood or impact of those failure modes...

Threat modeling AI applications

Proactively identifying, assessing, and addressing risk in AI systems We cannot anticipate every misuse or emergent behavior in AI systems. We can , however, identify what can go wrong, assess how bad it could be, and design systems that help reduce the likelihood or impact of those failure modes...

Developer-targeting campaign using malicious Next.js repositories

Microsoft Defender Experts identified a coordinated developer-targeting campaign delivered through malicious repositories disguised as legitimate Next.js projects and technical assessment materials. Telemetry collected during this investigation indicates the activity aligns with a broader cluster...

Developer-targeting campaign using malicious Next.js repositories

Microsoft Defender Experts identified a coordinated developer-targeting campaign delivered through malicious repositories disguised as legitimate Next.js projects and technical assessment materials. Telemetry collected during this investigation indicates the activity aligns with a broader cluster...

Scaling security operations with Microsoft Defender autonomous defense and expert-led services

Today’s security leaders are operating in an environment of truncated cyberattack timelines with aging defenses built for slower, linear cyberthreats that can no longer keep pace with advanced cyberthreats. AI-powered threat actors now use social engineering and malware that adapt in real time,...

New e-book: Establishing a proactive defense with Microsoft Security Exposure Management

Effective exposure management begins by illuminating and hardening risks across the entire attack surface. Some of the most meaningful shifts in security happen quietly—when teams take a clear look at their exposure landscape and acknowledge the gap between where they stand today and where they...

New e-book: Establishing a proactive defense with Microsoft Security Exposure Management

Effective exposure management begins by illuminating and hardening risks across the entire attack surface. Some of the most meaningful shifts in security happen quietly—when teams take a clear look at their exposure landscape and acknowledge the gap between where they stand today and where they...