Protecting credentials against social engineering: Cyberattack Series

Our story begins with a customer whose help desk unwittingly assisted a threat actor posing as a credentialed employee. In this fourth report in our ongoing Cyberattack Series, we look at the steps taken to discover, understand, and respond to a credential phishing and smishing text-based phishin...

Join us at InfoSec Jupyterthon 2022

Notebooks are gaining popularity in InfoSec. Used interactively for investigations and hunting or as scheduled processing jobs, notebooks offer plenty of advantages over traditional security operations center SOC tools. Sitting somewhere between scripting/macros and a full-blown development...

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...

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...

Test your team’s security readiness with the Gone Phishing Tournament

Why should you care about the behavioral risk of your employees? Eighty-two percent of breaches include and often start with user behavior.1 Not all are phishing, but a majority of them are just that. Phishing is, and has been for many years, the cheapest and most reliable way for an attacker of...

KuppingerCole rates Microsoft as outstanding in functionality for secure collaboration

We are excited to share that Microsoft has been rated "Outstanding in Functionality" in the KuppingerCole Market Compass for Secure Collaboration, May 2022. Microsoft was also the only company to be awarded the highest possible score of "Strong Positive" in all five categories: security,...

How one Microsoft software engineer works to improve access management

There’s still a perception that the most successful computer scientists learn programming at a young age, study engineering at a top school, and then get a software development job right out of college. While that’s how many people enter the field, it’s not the only path. Microsoft Software...

New security features for Windows 11 will help protect hybrid work

Attackers haven’t wasted any time capitalizing on the rapid move to hybrid work. Every day cybercriminals and nation-states alike have improved their targeting, speed, and accuracy as the world adapted to working outside the office. These changes have put "cybersecurity issues and risks” at the t...

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...

How to better protect your growing business in an AI-powered world

AI is rapidly reshaping how work gets done in companies and organizations. In celebrating National Small Business Month, we want to acknowledge the unique challenges that growing business leaders face as AI creates both opportunity and risk. They face constant tradeoffs between moving fast,...

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...

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...

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...

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...

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...

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...

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...

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...

Connect with the security community at Microsoft Ignite 2025

In today’s AI-powered world, security professionals are facing unprecedented challenges—and opportunities. As generative AI reshapes the digital landscape, the need for robust, intelligent, and adaptive security strategies has never been more urgent. At Microsoft Ignite 2025, we will showcase...

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...

Microsoft announces the 2025 Security Excellence Awards winners

In today’s rapidly evolving digital world, security requires a global community of defenders working together as a team to build a safer world for all. That’s why we’re thrilled to recognize the extraordinary individuals and organizations who have gone above and beyond in the fight against...

Join the new Microsoft Security experience at Microsoft Ignite 2023

During the past few years, we’ve managed a lot of change and disruption in our security work, in our lives, and in society at large. This year we’re excited to welcome back security leaders, aspiring leaders, and IT professionals—in person—to Microsoft Ignite from November 14 to 17, 2023, and...

Boost identity protection with Axiad Cloud and Microsoft Entra ID

This blog post is part of the Microsoft Intelligent Security Association guest blog series. Learn more about MISA. Passwords are a security weakness and phishing attacks to exploit accounts protected by passwords are on the rise. The last 12 months have seen an average of more than 4,000 password...

Microsoft Defender for Office 365 receives highest award in SE Labs Enterprise Email Security Services test

In today’s evolving threat landscape, email represents the primary attack vector for cybercrime, making effective email protection a key component of any security strategy.1 In Q1 2022, Microsoft participated in an evaluation of email security solutions, carried out by SE labs—a testing lab focus...

Making the world a safer place with Microsoft Defender for individuals

Today’s sophisticated cyber threats require a modern approach to security. And this doesn’t apply only to enterprises or government entities—in recent years we’ve seen attacks increase exponentially against individuals. There are 921 password attacks every second.1 We’ve seen ransomware threats...

Microsoft security experts outline next steps after compromise recovery

Who is CRSP? The Microsoft Compromise Recovery Security Practice CRSP is a worldwide team of cybersecurity experts operating in most countries, across both public and private organizations, with deep expertise to secure an environment post-security breach and to help you prevent a breach in the...

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...

Improve security with a Zero Trust access model

Zero Trust is a security model that I believe can begin to turn the tide in the cybersecurity battles. Traditional perimeter-based network security has proved insufficient because it assumes that if a user is inside the corporate perimeter, they can be trusted. We’ve learned that this isn't true...

Announcing Microsoft Defender ATP for Mac and new Threat and Vulnerability Management capabilities

On February 28, 2019, we announced Microsoft Threat Experts, a new managed hunting service within the Microsoft 365 Security portfolio that enables customers to extend their expertise and insights with the help of Microsoft security professionals. This release showcased our philosophy that securi...

Defending critical infrastructure is imperative

The Cybersecurity Tech Accord’s upcoming webinar and the importance of public-private partnership Today, cyberattacks from increasingly sophisticated actors threaten organizations across every sector, and whether a Fortune 500 company or a local bakery, organizations of all sizes need to take ste...

Understanding the performance impact of Spectre and Meltdown mitigations on Windows Systems

Last week the technology industry and many of our customers learned of new vulnerabilities in the hardware chips that power phones, PCs and servers. We and others in the industry had learned of this vulnerability under nondisclosure agreement several months ago and immediately began developing...

Turning threat intelligence into decisive action with Defender Experts

In this article 1. Upstream: See the campaign before it reaches you 1. In your environment: Follow the threat everywhere it moves 2. See it live at Black Hat USA Security teams have never had more visibility, yet rarely have they felt more uncertain. Signal pours in from endpoints, identities,...

Accelerating the quantum-safe timeline

The quantum-safe timeline has changed For years, planning for post-quantum cryptography PQC was framed as a future problem: important, inevitable, but distant. That perspective is evolving as technology advances and organizations prepare for the scale and complexity of the transition ahead. At...

Updating the taxonomy of failure modes in agentic AI systems: What a year of red teaming taught us

In this article 1. Why the Taxonomy Needed Updating 2. Seven new failure modes 3. Operational findings: What red teaming showed 4. New mitigations 5. What to do this quarter When the Microsoft AI Red Team published the Taxonomy of Failure Modes in Agentic AI Systems in April 2025, the goal was a...

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...

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...

Accelerating detection engineering using AI-assisted synthetic attack logs generation

In this article 1. Core Idea: From TTPs to Logs 2. Approaches for Synthetic Attack Log Generation 3. Evaluation Datasets 4. References 5. Learn more Logs and telemetry are the foundation of modern cybersecurity. They enable threat detection, incident response, forensic investigation, and complian...

Active attack: Dirty Frag Linux vulnerability expands post-compromise risk

In this article 1. Why Dirty Frag matters 2. Technical overview 3. Exploitation scenarios 4. Mitigation guidance 5. Post-mitigation integrity verification 6. References A newly disclosed Linux local privilege escalation vulnerability known as “Dirty Frag” enables escalation from an unprivileged...

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...

Investigating Storm-2755: “Payroll pirate” attacks targeting Canadian employees

In this article 1. Storm-2755’s attack chain 2. Defending against Storm-2755 and AiTM campaigns 3. Microsoft Defender detection and hunting guidance 4. Indicators of compromise Microsoft Incident Response – Detection and Response Team DART researchers observed an emerging, financially motivated...

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...

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...

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...

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,...

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 ...

Resurgence of a multi‑stage AiTM phishing and BEC campaign abusing SharePoint

Microsoft Defender Researchers uncovered a multi‑stage adversary‑in‑the‑middle AiTM phishing and business email compromise BEC campaign targeting multiple organizations in the energy sector, resulting in the compromise of various user accounts. The campaign abused SharePoint file‑sharing services...

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...

Microsoft Purview delivered 30% reduction in data breach likelihood

In today’s digital-first world, data is both an asset and a liability. As organizations scale their use of cloud platforms, AI, and remote collaboration tools, the complexity of managing data security, data privacy, and regulatory compliance grows exponentially. For organizations, the challenge i...

Microsoft at Black Hat USA 2025: A unified approach to modern cyber defense

Microsoft will be at Black Hat USA 2025, August 5–7 in Las Vegas, and we’re bringing you a unified, practitioner-driven experience built around real-world insights, threat intelligence, incident response, and hands-on AI expertise. We believe security teams are strongest when intelligence, tools,...