AI jailbreaks: What they are and how they can be mitigated

Generative AI systems are made up of multiple components that interact to provide a rich user experience between the human and the AI models. As part of a responsible AI approach, AI models are protected by layers of defense mechanisms to prevent the production of harmful content or being used to...

Microsoft introduces passkeys for consumer accounts

Ten years ago, Microsoft envisioned a bold future: a world free of passwords. Every year, we celebrate World Password Day by updating you on our progress toward eliminating passwords for good. Today, we’re announcing passkey support for Microsoft consumer accounts, the next step toward our vision...

Automatic disruption of human-operated attacks through containment of compromised user accounts

Our experience and insights from real-world incidents tell us that the swift containment of compromised user accounts is key to disrupting hands-on-keyboard attacks, especially those that involve human-operated ransomware. In these attacks, lateral movement follows initial access as the next...

Forrester names Microsoft a Leader in the 2023 Zero Trust Platform Providers Wave™ report

Microsoft is proud to be recognized as a Leader in the Forrester Wave™: Zero Trust Platform Providers, Q3 2023 report. At Microsoft, we understand modernizing security is a complex task in this era of ever-evolving cyberthreats and complex digital environments. Serious threats have necessitated a...

Microsoft Inspire: Partner resources to prepare for the future of security with AI

Cybersecurity is one of the most pressing challenges of our time. With an ever-changing threat landscape and siloed data across multiple security point solutions, defenders have limited visibility. It’s difficult to stay current and find cybersecurity professionals amid the global talent shortage...

How Microsoft and Sonrai integrate to eliminate attack paths

Cloud development challenges conventional thinking about risk. A “perimeter” was always the abstraction that security teams could start from—defining their perimeter and exposing the cracks in firewalls and network access. With more and more infrastructure represented as ephemeral code, protectin...

Discover a new era of security with Microsoft at RSAC 2023

We’re thrilled to participate and connect with you at RSA Conference 2023 RSAC from April 23 to 27, 2023, in San Francisco. Join your security peers as we welcome you to the new era of security—shaped by the power of OpenAI’s GPT-4 generative AI—and introduce to you the recently announced Microso...

SEC cyber risk management rule—a security and compliance opportunity

In my practice as a Microsoft Global Black Belt, I focus on the technical and business enablement aspects of protecting organizations from cyber threats with tools like Microsoft 365 Defender, Microsoft Purview and Microsoft Sentinel. In my role as a board member for another publicly traded...

Addressing cybersecurity at the board level with Difenda and Microsoft

This blog post is part of the Microsoft Intelligent Security Association guest blog series. Learn more about MISA. Cybersecurity is no longer simply a lone silo or regulatory process; it is a business issue that affects every aspect of an organization. From financial losses to reputational damage...

Do more with less with Microsoft Security—3 strategies to get you started

Relentless bad actors, evolving attack tactics, and numerous surfaces and endpoints that attackers may try to exploit. With the average cost of a data breach reaching an all-time high of USD4.35 million in 2022,1 protecting your people and data from adversaries is more important than ever. Plus,...

Cybersecurity awareness tips from Microsoft to empower your team to #BeCyberSmart

October is Cybersecurity Awareness Month, and I’m excited about what Microsoft and our partners in the industry have planned to help everyone stay CyberSmart. 2022 may have offered some respite from the previous year’s rush to enable a remote and hybrid workforce, but the increased use of persona...

Cybersecurity awareness tips from Microsoft to empower your team to #BeCyberSmart

October is Cybersecurity Awareness Month, and I’m excited about what Microsoft and our partners in the industry have planned to help everyone stay CyberSmart. 2022 may have offered some respite from the previous year’s rush to enable a remote and hybrid workforce, but the increased use of persona...

Using Python to unearth a goldmine of threat intelligence from leaked chat logs

Dealing with a great amount of data can be time consuming, thus using Python can be very powerful to help analysts sort information and extract the most relevant data for their investigation. The open-source tools library, MSTICPy, for example, is a Python tool dedicated to threat intelligence. I...

Secure your OT and IoT devices with Microsoft Defender for IoT and Quzara Cybertorch™

This blog post is part of the Microsoft Intelligent Security Association guest blog series. Learn more about MISA. In recent years, malicious actors have started attacking industrial control systems and key sectors of nations’ critical infrastructure to inflict damage that transcends the cyber...

Measure the effectiveness of your Microsoft security with AttackIQ

This blog post is part of the Microsoft Intelligent Security Association guest blog series. Learn more about MISA. To improve an organization’s cybersecurity readiness, you need to test that your detection and prevention technologies work as intended and that your security program is performing a...

What you need to know about how cryptography impacts your security strategy

The security community is continuously changing, growing, and learning from each other to better position the world against cyber threats. In the latest post of our Voice of the Community blog series post, Microsoft Security Product Marketing Manager Natalia Godyla talks with Taurus SA Co-founder...

HTML smuggling surges: Highly evasive loader technique increasingly used in banking malware, targeted attacks

HTML smuggling, a highly evasive malware delivery technique that leverages legitimate HTML5 and JavaScript features, is increasingly used in email campaigns that deploy banking malware, remote access Trojans RATs, and other payloads related to targeted attacks. Notably, this technique was observe...

Afternoon Cyber Tea: Learn how to stop misinformation threats from nation-state bad actors

Information has long been wielded as an instrument of national power and influence. In today’s digital world, misinformation can also be just as powerful. On a special episode of Afternoon Cyber Tea with Ann Johnson, Sandra Joyce, Executive Vice President and Head of Mandiant Intelligence at...

Microsoft Joins Open Source Security Foundation

Microsoft has invested in the security of open-source software for many years and today I’m excited to share that Microsoft is joining industry partners to create the Open Source Security Foundation OpenSSF, a new cross-industry collaboration hosted at the Linux Foundation. The OpenSSF brings...

Microsoft acquires CyberX to accelerate and secure customers’ IoT deployments

Today, we’re excited to announce that Microsoft has acquired CyberX, a comprehensive, network-based IoT security platform with continuous threat monitoring and sophisticated analytics that addresses IoT security in a holistic way across the enterprise. CyberX will complement the existing Azure Io...

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...

First things first: Envisioning your security deployment

This blog post is part of a series that responds to common questions we receive from customers about deployment of Microsoft 365 Security solutions. In this series youll find context, answers, and guidance for deployment and driving adoption within your organization. Check out our last blog...

Detecting reflective DLL loading with Windows Defender ATP

Today's attacks put emphasis on leaving little, if any, forensic evidence to maintain stealth and achieve persistence. Attackers use methods that allow exploits to stay resident within an exploited process or migrate to a long-lived process without ever creating or relying on a file on disk. In...

Counterfeit installers to system compromise: Tracking a deceptive software download campaign

In this article 1. Attack chain overview 2. Campaign scope and targeting 3. Mitigation and protection guidance 4. References 5. Learn more Microsoft Defender Experts is tracking an active malware campaign that uses counterfeit software-download websites to impersonate trusted vendors and distribu...

Chromium extension uses AI‑related branding to redirect browser search

In this article 1. Extension overview 2. Key indicators of malicious behavior 3. Dynamic analysis findings 4. Mitigation and protection guidance 5. References 6. Learn more Microsoft Threat Intelligence has identified a malicious Chromium-based extension that spoofs the AI-powered answer engine...

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...

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...

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...

Securing CI/CD in an agentic world: Claude Code Github action case

Microsoft Threat Intelligence discovered that Anthropic's Claude Code GitHub Action could expose CI/CD workflow secrets when AI agents process untrusted GitHub content, including issue bodies, pull request descriptions, and comments. We found that while Claude Code Action supported environment...

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...

Microsoft Build 2026: Securing code, agents, and models across the development lifecycle

In this article 1. Secure your code 2. Secure your agents 3. Trust agents with your data 4. Secure your models 5. Trust starts with security Today, developers and security teams are caught in growing tension. AI is accelerating development and introducing new issues around insecure code, opaque...

Exposing Fox Tempest: A malware-signing service operation

In this article 1. Fox Tempest’s role and impact 2. Fox Tempest’s malware signing as a service infrastructure 3. Defending against Fox Tempest-enabled attacks 4. Microsoft Defender detections 5. Indicators of compromise Fox Tempest is a financially motivated threat actor that operates a...

World Passkey Day: Advancing passwordless authentication

World Passkey Day is a chance to reflect on progress toward a shared goal: reducing our reliance on passwords and other phishable authentication methods by accelerating passkey adoption. As cyberattacks become more automated and AI-powered, each account is only as secure as its weakest credential...

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...

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...

Dissecting Sapphire Sleet’s macOS intrusion from lure to compromise

In this article 1. Sapphire Sleet’s campaign lifecycle 2. Defending against Sapphire Sleet intrusion activity 3. Microsoft Defender detection and hunting guidance 4. Indicators of compromise Executive summary Microsoft Threat Intelligence uncovered a macOS‑focused cyber campaign by the North Kore...

Mitigating the Axios npm supply chain compromise

In this article 1. Analysis of the attack 2. Mitigation and protection guidance 3. Microsoft Defender detections 4. Indicators of compromise 5. Hunting queries On March 31, 2026, two new npm packages for updated versions of Axios, a popular HTTP client for JavaScript that simplifies making HTTP...

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...

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...

Phishing actors exploit complex routing and misconfigurations to spoof domains

Phishing actors are exploiting complex routing scenarios and misconfigured spoof protections to effectively spoof organizations’ domains and deliver phishing emails that appear, superficially, to have been sent internally. Threat actors have leveraged this vector to deliver a wide variety of...

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...

Cybersecurity strategies to prioritize now​​

The Deputy CISO blog series is where Microsoft 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...

SesameOp: Novel backdoor uses OpenAI Assistants API for command and control

Microsoft Incident Response – Detection and Response Team DART researchers uncovered a new backdoor that is notable for its novel use of the OpenAI Assistants Application Programming Interface API as a mechanism for command-and-control C2 communications. Instead of relying on more traditional...

Investigating active exploitation of CVE-2025-10035 GoAnywhere Managed File Transfer vulnerability

On September 18, 2025, Fortra published a security advisory regarding a critical deserialization vulnerability in GoAnywhere MFT's License Servlet, which is tracked as CVE-2025-10035 and has a CVSS score of 10.0. The vulnerability could allow a threat actor with a validly forged license response...

Transparency on Microsoft Defender for Office 365 email security effectiveness

In today’s world, cyberattackers are relentless. They are often well-resourced, highly sophisticated, and constantly innovating, which means the effectiveness of cybersecurity solutions must be continuously evaluated, not assumed. Yet, despite the critical role email security plays in protecting...

Microsoft Security Copilot drives new product integrations at Microsoft Ignite to empower security and IT teams

First announced in March 2023, Microsoft Security Copilot—Microsofts first generative AI security product—has sparked major interest. The widespread enthusiasm was on full display after announcing our Early Access Program in October 2023 and sharing our incredible Security Copilot innovations at...

Top insights and best practices from the new Microsoft Data Security Index report

A whopping 74 percent of organizations recently surveyed experienced at least one data security incident with their business data exposed in the previous year. That’s just one of our interesting insights from Microsoft’s new Data Security Index: Trends, insights, and strategies to secure data...

New Microsoft security tools to protect families and businesses

Today marks an exciting milestone in Microsoft’s AI journey. This morning, at an event in New York City, we made several major announcements to empower people across work and life—you can read more about Microsoft Bing and Edge with Copilot, what’s new from Microsoft 365 Copilot and Bing Chat...

Flax Typhoon using legitimate software to quietly access Taiwanese organizations

Summary Microsoft has identified a nation-state activity group tracked as Flax Typhoon, based in China, that is targeting dozens of organizations in Taiwan with the likely intention of performing espionage. Flax Typhoon gains and maintains long-term access to Taiwanese organizations networks with...