Microsoft protects against human-operated ransomware across the full attack chain in the 2022 MITRE Engenuity ATT&CK® Evaluations

For the fourth year in a row, the independent MITRE Engenuity Adversarial Tactics, Techniques, and Common Knowledge ATT&CK® Evaluations demonstrated Microsoft’s strong detection and protection capabilities thanks to our multi-platform extended detection and response XDR defenses. The ever-evolvin...

2.5 million-plus cybersecurity jobs are open—women can fill them

This month is Women’s History Month and today is International Women’s Day—a time to reflect as individuals, societies, and industries on our progress for quality and equity for women. As a woman working in cybersecurity, I know firsthand that engaging girls, women, and people of color in...

Discover what’s new and gain technical expertise from MISA at Ignite

It’s hard to believe we’re so close to the end of another year, and what a year it’s been. For too brief a time in some places, our masks were tossed away, only to find us digging them out of drawers again not long after. But masked up or not, it’s been good to see local restaurants buzzing with...

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...

Optimize security with Azure Firewall solution for Azure Sentinel

Security is a constant balance between proactive and reactive defenses. They are both equally important, and neither can be neglected. Effectively protecting your organization means constantly optimizing both prevention and detection. That’s why we’re excited to announce a seamless integration...

Building a world without passwords

Nobody likes passwords. They are inconvenient, insecure, and expensive. In fact, we dislike them so much that weve been busy at work trying to create a world without them a world without passwords. In this blog, we will provide a brief insight into how we at Microsoft think about solving this...

Application fuzzing in the era of Machine Learning and AI

Proactively testing software for bugs is not new. The earliest examples date back to the 1950s with the term fuzzing. Fuzzing as we now refer to it is the injection of random inputs and commands into applications. It made its debut quite literally on a dark and stormy night in 1988. Since then,...

How public-private partnerships can combat cyber adversaries

For several years now, policymakers and practitioners from governments, CERTs, and the security industry have been speaking about the importance of public-private partnerships as an essential part of combating cyber threats. It is impossible to attend a security conference without a keynote...

Microsoft named a leader in the Frost Radar for cloud and application runtime security

Cloud security is shifting from visibility to contextual risk reduction, extending into the applications, APIs, and workloads where attacks actually occur. Because modern workloads are built and run in the cloud, security teams must understand which exposures matter most, prioritize what can trul...

AI is accelerating cyberattacks—here’s how to stay ahead

In March, we wrote that identity security has become the new pressure point for modern cyberattacks. Since then, AI has only increased that pressure. AI helps cyberattackers move faster across the attack chain: personalizing social engineering at scale, automating reconnaissance, analyzing leaked...

AI is accelerating cyberattacks—here’s how to stay ahead

In March, we wrote that identity security has become the new pressure point for modern cyberattacks. Since then, AI has only increased that pressure. AI helps cyberattackers move faster across the attack chain: personalizing social engineering at scale, automating reconnaissance, analyzing leaked...

Turn specs into evals for any agent with ASSERT

Today, we’re releasing Adaptive Spec-driven Scoring for Evaluation and Regression Testing ASSERT, an open-source framework for turning natural-language behavior specifications into executable evaluations. Every team building an AI system starts with a clear intention for the behaviors they want t...

Preinstall to persistence: Inside the Red Hat npm Miasma credential-stealing campaign

In this article 1. Attack chain overview 2. Mitigation and protection guidance 3. Learn more Microsoft Threat Intelligence identified a large-scale npm supply chain attack affecting 32 maliciously modified packages across more than 90 versions under the @redhat-cloud-services npm scope. The...

From poisoned search results to GPU mining: A cryptojacking campaign abusing ScreenConnect and Microsoft .NET utilities

In this article 1. Attack chain overview 2. Mitigation and protection guidance 3. References 4. Learn more Microsoft Defender Experts identified an active cryptojacking campaign in which malicious download sites are surfaced not only through traditional search engine poisoning, but also through A...

Introducing RAMPART and Clarity: Open source tools to bring safety into Agent development workflow

In this article 1. Why we are investing in this 2. RAMPART: Continuous safety testing for agentic AI 3. Clarity: Helping check software engineering assumptions 4. RAMPART and Clarity available now The AI systems shipping inside enterprises today are fundamentally different from the ones we were...

Defense in depth for autonomous AI agents

Designing Secure Autonomous AI Agents with Defense in Depth AI agents are moving beyond assistance and into action. Instead of generating content, they invoke tools, modify data, trigger workflows, and operate across systems with increasing autonomy. This shift changes the security problem...

Undermining the trust boundary: Investigating a stealthy intrusion through third-party compromise

In this article 1. Abuse of trusted relationships as an attack delivery mechanism 2. Methods, tools, and access strategies 3. Campaign conclusion 4. Microsoft Defender detection and hunting guidance In recent years, many sophisticated intrusions have increasingly avoided using noisy exploits,...

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...

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...

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...

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...

Detecting backdoored language models at scale

Today, we are releasing new research on detecting backdoors in open-weight language models. Our research highlights several key properties of language model backdoors, laying the groundwork for a practical scanner designed to detect backdoored models at scale and improve overall trust in AI...

Defending against the CVE-2025-55182 (React2Shell) vulnerability in React Server Components

CVE-2025-55182 also referred to as React2Shell and includes CVE-2025-66478, which was merged into it is a critical pre-authentication remote code execution RCE vulnerability affecting React Server Components, Next.js, and related frameworks. With a CVSS score of 10.0, this vulnerability could all...

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...

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...

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...

Malvertising campaign leads to info stealers hosted on GitHub

In early December 2024, Microsoft Threat Intelligence detected a large-scale malvertising campaign that impacted nearly one million devices globally in an opportunistic attack to steal information. The attack originated from illegal streaming websites embedded with malvertising redirectors, leadi...

New Microsoft Incident Response team guide shares best practices for security teams and leaders

As enterprise networks grow in both size and complexity, securing them from motivated cyberthreat actors becomes more challenging. The incident response process can be a maze that security professionals must quickly learn to navigate—which is no easy task. Surprisingly, many organizations still...

Cyber Signals: Sporting events and venues draw cyberthreats at increasing rates

Today we released the fifth edition of Cyber Signals, spotlighting threats to large venues, and sporting and entertainment events, based on our learnings and telemetry from delivering cybersecurity support to critical infrastructure facilities during the State of Qatar’s hosting of the FIFA World...

Microsoft at NICE Conference: Resetting expectations and enabling diversity in the cybersecurity workforce

Closing the cybersecurity talent gap is not something we can achieve alone; it requires a collective effort from the entire industry and focus on enabling cybersecurity awareness and education for all. This realization hit home for us during our recent participation in the National Initiative for...

5 cybersecurity capabilities announced at Microsoft Ignite 2022 to help you secure more with less

Protecting your business against growing security threats is a huge priority. Companies of all sizes have increased their spending on cybersecurity solutions to protect their operations over the last year. User spending for the information security and risk management market will grow to USD169.2...

Microsoft publishes new report on holistic insider risk management

The risk landscape for organizations has changed significantly in the past few years. The amount of data captured, copied, and consumed is expected to grow to more than 180 zettabytes through 2025.1 Traditional ways of identifying and mitigating risks don’t always work. Historically, organization...

Introducing security for unmanaged devices in the Enterprise network with Microsoft Defender for IoT

How many IoT devices are used at your company? If yours is like most organizations, there are probably printers, scanners, and fax machines scattered around the office. Perhaps smart TVs are mounted at reception or in the break room to guide visitors and keep employees up-to-date on company event...

3 strategies to launch an effective data governance plan

Aware of the potential risks of sensitive data if not managed properly, you’ve undertaken a data discovery process to learn where it’s all stored. You’ve classified this sensitive data—confidential information like credit card numbers and home addresses collected from customers, prospects,...

Gartner names Microsoft a Leader in the 2019 Cloud Access Security Broker (CASB) Magic Quadrant

In Gartner’s third annual Magic Quadrant for Cloud Access Security Brokers CASB, Microsoft was named a Leader based on its completeness of vision and ability to execute in the CASB market. Microsoft was also identified as strongest in execution. Gartner led the industry when they defined the term...

Detonating a bad rabbit: Windows Defender Antivirus and layered machine learning defenses

Windows Defender Antivirus uses a layered approach to protection: tiers of advanced automation and machine learning models evaluate files in order to reach a verdict on suspected malware. While Windows Defender AV detects a vast majority of new malware files at first sight, we always strive to...

A decade inside Microsoft Security

Ten years ago, I walked onto Microsofts Redmond campus to take a role on a team that partnered with governments and CERTs on cybersecurity. Id just left a meaningful career in US federal government service because I thought it would be fascinating to experience first-hand the security challenges...

Crypto Clipper uses Tor and worm-like propagation for persistence and control

In this article 1. Attack chain overview 2. Mitigation and protection guidance 3. References 4. Learn more Microsoft Threat Intelligence and Microsoft Defender Experts identified a Windows-based cryptocurrency clipper that has affected users since February of 2026. Clipper malware relies on...

Reconstructing AI activity in investigations

AI systems are now part of everyday work. Investigators need a consistent way to reconstruct what happened within them. Security teams are already investigating activity involving Microsoft 365 Copilot and Azure AI services—from prompt injection attempts to unexpected data access. Those signals a...

Kazuar: Anatomy of a nation-state botnet

In this article 1. Delivery 2. Module types 3. Botnet operations 4. Who is Secret Blizzard? 5. Mitigation and protection guidance 6. Microsoft Defender detections Kazuar, a sophisticated malware family attributed to the Russian state actor Secret Blizzard, has been under constant development for...

When configuration becomes a vulnerability: Exploitable misconfigurations in AI apps

In this article 1. Background 2. What is an exploitable misconfiguration? 3. Exploitable misconfigurations in popular AI applications 4. Minimizing the risk: Practical deployment guidance 5. How Microsoft Defender for Cloud helps detect exposures in Kubernetes 6. Learn more AI and agentic...

CVE-2026-31431: Copy Fail vulnerability enables Linux root privilege escalation across cloud environments

In this article 1. Vulnerability details 2. Mitigation and protection guidance 3. Microsoft Defender XDR detections 4. References 5. Learn more Microsoft Defender is investigating a high-severity local privilege escalation vulnerability CVE-2026-31431 affecting multiple major Linux distributions...

Unify now or pay later: New research exposes the operational cost of a fragmented SOC

Security operations are entering a pivotal moment: the operating model that grew around network logs and phishing emails is now buckling under tool sprawl, manual triage, and threat actors that outpace defender capacity. New research from Microsoft and Omdia shows just how heavy the burden can...

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...

Extortion and ransomware drive over half of cyberattacks

In 80% of the cyber incidents Microsoft’s security teams investigated last year, attackers sought to steal data—a trend driven more by financial gain than intelligence gathering. According to the latest Microsoft Digital Defense Report, written with our Chief Information Security Officer Igor...

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...

Microsoft is named a Leader in the 2025 Gartner® Magic Quadrant™ for Endpoint Protection Platforms

Since 2022, the number of human-operated ransomware-linked encounters by organizations surged by 2.75x. Yet, Microsoft Defender for Endpoint has outpaced this rise, reducing the number of successful attacks by 3x, proving its power to turn the tide against evolving cyberthreats.1 Defender for...

Pushing passkeys forward: Microsoft’s latest updates for simpler, safer sign-ins

Happy World Passkey Day! As the world shifts from passwords to passkeys, we’re excited to join the FIDO Alliance in leaving “World Password Day” behind to celebrate the very first “World Passkey Day.” To commemorate this renaming, Microsoft and dozens of other organizations have taken the Passkey...

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...