Passkey-themed social engineering leads to identity and cloud compromise

In this article 1. Attack chain overview 2. Attribution 3. Mitigation and protection guidance 4. Learn more Microsoft Security Research is tracking active cloud-based intrusions spanning multiple accounts in which unusual sign-ins were followed by threat actor-added authentication methods,...

Hunting MacSync Stealer infrastructure through behavioral pivots

In this article 1. Activity overview 2. Discovery of additional rotating infrastructure 3. Attack chain overview 4. Mitigation and protection guidance 5. References 6. Learn more MacSync Stealer is a macOS-focused information stealer that relies on changing infrastructure to deliver payloads,...

Advance Zero Trust for AI: New tools and guidance to secure AI agents and DevSecOps

The calculus of cybersecurity has changed. AI is reshaping how organizations build, deploy, operate, and defend digital systems. AI-powered development tools, agents, and autonomous workflows are accelerating innovation but they are also introducing new attack surfaces, new trust boundaries, and...

ACR Stealer: Two observed intrusion chains amid increased threat activity

In this article 1. Campaign 1: WebDAV-based ClickFix with Python loaders and blockchain C2 2. Campaign 2: MSHTA-initiated PowerShell chain with steganographic payload delivery 3. Mitigation and protection guidance 4. References 5. Learn more From late April 2026 to mid-June 2026, Microsoft Defend...

Microsoft a Leader in The Forrester Wave™ for Endpoint Management Platforms

The endpoint management category is being redefined in real time. Organizations no longer need tools that only inventory devices or enforce configuration policies; they need a platform that connects identity, security, compliance, and AI governance across every endpoint where work happens...

Malicious npm packages abuse dependency confusion to profile developer environments

In this article 1. Attack chain overview 2. Threat actor attribution 3. Mitigation and protection guidance 4. Indicators of Compromise IOC 5. References 6. Learn more Microsoft Threat Intelligence has uncovered an active supply chain attack involving malicious npm packages registered under...

Defending consumer web properties against modern DDoS attacks

If you own, create, or maintain online services and web portals, you’re probably aware of the dramatic upswing in DDoS attacks on your domains. AI has democratized tooling not just for us but for threat actors as well. DDoS in this era has extended from simple bandwidth saturation to sophisticate...

Detection strategies across cloud and identities against infiltrating IT workers

In this article 1. Attack chain overview 1. Activities in pre-recruitment phase 2. Activities in recruiting phase 3. Activities in post-recruitment phase 2. Mitigation and protection guidance 3. Microsoft Defender XDR detections The shift to remote and hybrid work since the pandemic expanded glob...

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...

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...

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...

New Clickfix variant ‘CrashFix’ deploying Python Remote Access Trojan

In January 2026, Microsoft Defender Experts identified a new evolution in the ongoing ClickFix campaign. This updated tactic deliberately crashes victims’ browsers and then attempts to lure users into executing malicious commands under the pretext of restoring normal functionality. This variant...

Case study: Securing AI application supply chains

The rapid adoption of AI applications, including agents, orchestrators, and autonomous workflows, represents a significant shift in how software systems are built and operated. Unlike traditional applications, these systems are active participants in execution. They make decisions, invoke tools,...

New Microsoft Data Security Index report explores secure AI adoption to protect sensitive data

Generative AI and agentic AI are redefining how organizations innovate and operate, unlocking new levels of productivity, creativity and collaboration across industry teams. From accelerating content creation to streamlining workflows, AI offers transformative benefits that empower organizations ...

Microsoft named an overall leader in KuppingerCole Leadership Compass for Generative AI Defense

Today, we are proud to share that Microsoft has been recognized as an overall leader in the KuppingerCole Leadership Compass for Generative AI Defense GAD, an independent report from a leading European analyst firm. This recognition reinforces the work we’ve been doing to deliver enterprise-ready...

Retail at risk: How one alert uncovered a persistent cyberthreat​​

In the latest edition of our Cyberattack Series, we dive into real-world cases targeting retail organizations. With 60% of retail companies reporting operational disruptions from cyberattacks and 43% experiencing security compromises in the past year, the risks for businesses continue to increase...

How Microsoft Defender for Endpoint is redefining endpoint security

Securing your digital estate with endpoint detection and response EDR across all platforms, devices, and Internet of Things IoT has never been more challenging. A rapidly evolving cyberthreat landscape has seen cyberattacks grow in sophistication, evolving from randomized single domain cyberattac...

Threat actors leverage tax season to deploy tax-themed phishing campaigns

As Tax Day approaches in the United States on April 15, Microsoft has observed several phishing campaigns using tax-related themes for social engineering to steal credentials and deploy malware. These campaigns notably use redirection methods such as URL shorteners and QR codes contained in...

Protect intellectual property with Govern 365 and Microsoft Purview

This blog post is part of the Microsoft Intelligent Security Association guest blog series. Learn more about MISA. Global supply chains face a broad range of risks, from physical threats to cybersecurity threats. Sharing information with suppliers is essential for the supply chain to function...

See product news and on-demand sessions from Microsoft Secure

“Great speakers and very knowledgeable.” “Brilliant.” “Wonderful and very useful.” The first Microsoft Secure on March 28, 2023, was a huge success—as this attendee feedback shows. Our virtual event brought together more than 20,000 security professionals eager to learn security best practices an...

Introducing new Microsoft Defender for Cloud innovations to strengthen cloud-native protections

Security teams face an expanding attack surface as organizations increasingly use cloud-native services to develop, deploy, and manage applications across their multicloud and hybrid environments. Their challenge is compounded by incomplete visibility, siloed processes, and a lack of prioritized...

ZINC weaponizing open-source software

In recent months, Microsoft has detected a wide range of social engineering campaigns using weaponized legitimate open-source software by an actor we track as ZINC. Microsoft Threat Intelligence Center MSTIC observed activity targeting employees in organizations across multiple industries includi...

Secure your endpoints with Transparity and Microsoft

This blog post is part of the Microsoft Intelligent Security Association guest blog series. Learn more about MISA. Endpoint protection platforms EPPs are dead and no longer sufficient to protect your organization, right? Wrong. When it comes to cybersecurity, the ability to normalize and correlat...

Connect with Microsoft Security experts at the 2022 Gartner Identity & Access Management Summit

The transition to a remote and hybrid workforce happened fast during a time of uncertainty, and IT professionals rose to the challenge with ingenuity and dedication. But two years in, many IT teams are still responding with patchwork solutions to enforce identity and access management IAM across ...

Discover the anatomy of an external cyberattack surface with new RiskIQ report

The internet is now part of the network. That might sound like hyperbole, but the massive shift to hybrid and remote work and a multicloud environment means security teams must now defend their entire online ecosystem. Recent ransomware attacks against internet-facing systems have served as a...

Microsoft unpacks comprehensive security at Gartner and Forrester virtual events

Every day, Microsoft is committed to maintaining comprehensive security for all across our interconnected global community. With that purpose in mind, we recently sponsored the 2021 Gartner Security and Risk Summit and 2021 Forester Security and Risk Forum, where we discussed ongoing changes in t...

Afternoon Cyber Tea: Microsoft’s cybersecurity response to COVID-19

On February 25, 2020, Microsoft Chief Information Security Officer CISO Bret Arsenault was attending the RSA Conference in San Francisco when the city declared a state of emergency because of COVID-19. Shortly after flying back to Seattle, Bret learned of the first death from the coronavirus in...

Behind the scenes of business email compromise: Using cross-domain threat data to disrupt a large BEC campaign

Microsoft 365 Defender researchers recently uncovered and disrupted a large-scale business email compromise BEC infrastructure hosted in multiple web services. Attackers used this cloud-based infrastructure to compromise mailboxes via phishing and add forwarding rules, enabling these attackers to...

Impersonating IT support: how threat actors turn a remote session into enterprise-wide access

In this article 1. Risk to enterprise environments 2. Attack chain overview 3. Mitigation and response recommendations 4. Learn more Microsoft Threat Intelligence has observed a human-operated intrusion campaign that abuses Microsoft Teams external collaboration to impersonate IT or helpdesk...

DeadLock ransomware: Breaking down a Rust-based encryptor with decentralized recovery infrastructure

In this article 1. Pre-encryption 2. Encryption 3. Post-encryption 4. Defending against DeadLock ransomware 5. Indicators of compromise Microsoft Threat Intelligence tracks DeadLock ransomware as an emerging financially motivated operation distinguished by its use of decentralized infrastructure ...

ChainDrop supply chain compromise: Anatomy of a self-propagating worm

In this article 1. Attack chain overview 2. Mitigation and protection guidance 3. Indicators of compromise IOC 4. Microsoft Defender XDR detections 5. Advanced hunting queries 6. Learn more Microsoft Threat Intelligence identified a large-scale npm supply chain attack affecting more than 400...

CaptiveCrunch: Midnight Blizzard targets travelers worldwide for malware delivery and credential theft

In this article 1. The CaptiveCrunch campaign 2. Storm-2945 and Midnight Blizzard 3. CaptiveCrunch tradecraft and tooling 4. How to protect against CaptiveCrunch activity 5. Microsoft Defender detections and hunting guidance 6. Indicators of compromise Since early May 2026, Microsoft Threat...

Simplifying AWS defense with Microsoft Sentinel UEBA

In this article 1. Under the hood: The tables 2. Traditional vs. new approach 3. Real-world attack scenarios: Microsoft Sentinel UEBA in action 4. Practical implementation: Getting started 5. Limitations and constraints 6. From raw logs to behavioral context With the expansion of Microsoft Sentin...

The threat to critical infrastructure has changed. Has your readiness?

Critical infrastructure CI organizations underpin national security, public safety, and the economy. In 2026, the cyber threat landscape facing these sectors is structurally different than it was even two years ago. What Microsoft Threat Intelligence is observing across critical infrastructure...

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...

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,...

The strategic SIEM buyer’s guide: Choosing an AI-ready platform for the agentic era

As the agentic era reshapes security operations, leaders face a strategic inflection point: legacy security information and event management SIEM solutions and fragmented toolchains can no longer keep pace with the scale, speed, and complexity of modern cyberthreats. Organizations can choose to...

80% of Fortune 500 use active AI Agents: Observability, governance, and security shape the new frontier

Today, Microsoft is releasing the new Cyber Pulse report to provide leaders with straightforward, practical insights and guidance on new cybersecurity risks. One of today’s most pressing concerns is the governance of AI and autonomous agents. AI agents are scaling faster than some companies can s...

Analysis of active exploitation of SolarWinds Web Help Desk

The Microsoft Defender Research Team observed a multi‑stage intrusion where threat actors exploited internet‑exposed SolarWinds Web Help Desk WHD instances to get an initial foothold and then laterally moved towards other high-value assets within the organization. However, we have not yet confirm...

Case study: Securing AI application supply chains

The rapid adoption of AI applications, including agents, orchestrators, and autonomous workflows, represents a significant shift in how software systems are built and operated. Unlike traditional applications, these systems are active participants in execution. They make decisions, invoke tools,...

From runtime risk to real‑time defense: Securing AI agents

AI agents, whether developed in Microsoft Copilot Studio or on alternative platforms, are becoming a powerful means for organizations to create custom solutions designed to enhance productivity and automate organizational processes by seamlessly integrating with internal data and systems. From a...

Introducing the Microsoft Defender Experts Suite: Elevate your security with expert-led services

Security teams are being pushed to their limits as AI‑powered cyberattacks grow in speed, scale, and sophistication—and only 14% of organizations surveyed by the World Economic Forum report they feel confident they have the right people and skills needed to meet their cybersecurity objectives.1 A...

Changing the physics of cyber defense

The Deputy CISO blog series is whereMicrosoft Deputy Chief Information Security Officers CISOs share their thoughts on what is most important in their respective domains. In this series, you will get practical advice, tactics to start and stop deploying, forward-looking commentary on where the...

​​Learn what generative AI can do for your security operations center

The busier security teams get, the harder it can be to understand the full impact of false positives, queue clutter, tool fragmentation, and more. But what is clear—it all adds up to increased fatigue and an increased potential to miss the cyberthreats that matter most. To help security teams...

Investigating targeted “payroll pirate” attacks affecting US universities

Microsoft Threat Intelligence has observed a financially motivated threat actor that we track as Storm-2657 compromising employee accounts to gain unauthorized access to employee profiles and divert salary payments to attacker-controlled accounts. These types of attacks have been dubbed “payroll...

Discover how automatic attack disruption protects critical assets while ensuring business continuity

Traditional security solutions often operate in a one-size-fits-all alert model that treats every detection equally, regardless of how important the asset is. But not all assets are equal. Critical assets are systems governing access, identity, or sensitive data. They are essential to an...

The ultimate guide to Microsoft Security at RSAC 2025

The Ultimate Guide to Microsoft Security at RSAC 2025 So you just finished watching Microsoft Secure. That means by now, you’ve heard about our new protections for AI and Microsoft Security Copilot agents. These innovations will be the focus of Microsoft Security’s sessions and activities at RSAC...

How cyberattackers exploit domain controllers using ransomware

In recent years, human-operated cyberattacks have undergone a dramatic transformation. These attacks, once characterized by sporadic and opportunistic attacks, have evolved into highly sophisticated, targeted campaigns aimed at causing maximum damage to organizations, with the average cost of a...

Tech Accelerator: Azure security and AI adoption

Are you looking for guidance on how to effectively integrate security best practices within your Azure and AI projects? We know the pace of technological innovation offers as many opportunities as it does challenges. However, security cannot be an afterthought as you create Azure deployments and...