How Storm-2949 turned a compromised identity into a cloud-wide breach

In this article 1. Attack chain overview 1. Cloud compromise: Microsoft Entra ID and Microsoft 365 2. Initial access and persistence through targeted social engineering and SSPR abuse 3. Directory discovery and persistence 4. Microsoft 365 discovery and exfiltration 5. Cloud compromise: Microsoft...

Blue teams helping red teams: A tale of a process crash, PowerShell, and the MITRE ATT&CK evaluation

In September 2019, MITRE evaluated Microsoft Threat Protection MTP and other endpoint security solutions. The ATT&CK evaluation lasted for three days, with a professional red team from MITRE emulating many advanced attack behaviors used by the nation-state threat group known as YTTRIUM APT29. Aft...

Multi-stage downloader Trojan sLoad abuses BITS almost exclusively for malicious activities

Many of today’s threats evolve to incorporate as many living-off-the-land techniques as possible into the attack chain. The PowerShell-based downloader Trojan known as sLoad, however, puts all its bets on BITS. Background Intelligent Transfer Service BITS is a component of the Windows operating...

What’s new in Windows Defender ATP

Across Windows Defender Advanced Threat Protection Windows Defender ATP engineering and research teams, innovation drives our mission to protect devices in the modern workplace. Our goal is to equip security teams with the tools and insights to protect, detect, investigate, and automatically...

Step 10. Detect and investigate security incidents: top 10 actions to secure your environment

"Step 10. Detect and investigate security incidents" is the final installment in the Top 10 actions to secure your environment blog series. Here we walk you through how to set up Azure Advanced Threat Protection Azure ATP to secure identities in the cloud and on-premises. Azure ATP is a service i...

Council of EU Law Enforcement Protocol improves cross-border cooperation

Last March, the Council of the European Union announced the new EU Law Enforcement Emergency Response Protocol to address the growing problem of planning and coordinating between governments, agencies, and companies when cyberattacks occur across international boundaries. Remember well-known...

Microsoft Intelligent Security Association welcomes members of the Microsoft Virus Initiative

As we head into our annual partner conference, Microsoft Inspire, I’m excited to make a major announcement! The Microsoft Virus Initiative MVI is formally joining the Microsoft Intelligent Security Association MISA. For more than 20 years, Microsoft and our antimalware partners have collaborated...

Azure Sentinel—the cloud-native SIEM that empowers defenders is now generally available

Machine learning enhanced with artificial intelligence AI holds great promise in addressing many of the global cyber challenges we see today. They give our cyber defenders the ability to identify, detect, and block malware, almost instantaneously. And together they give security admins the abilit...

Top 10 security steps in Microsoft 365 that political campaigns can take today

The increasing frequency of cyberattacks make clear that more must be done to protect key democratic institutions from cyber-enabled interference. Withjust a fewweeks left before theU.S.midtermelections and early voting under way,campaignsmust stay vigilant in protecting against cyberattacks to...

Step 2. Manage authentication and safeguard access: top 10 actions to secure your environment

This series outlines the most fundamental steps you can take with your investment in Microsoft 365 security solutions. We will provide advice on activities such as setting up identity management through active directory, malware protection, and more. In this post, we explain how to enable single...

Guidance for investigating attacks using CVE-2022-21894: The BlackLotus campaign

This guide provides steps that organizations can take to assess whether users have been targeted or compromised by threat actors exploiting CVE-2022-21894 via a Unified Extensible Firmware Interface UEFI bootkit called BlackLotus. UEFI bootkits are particularly dangerous as they run at computer...

Key layers for developing a Smarter SOC with CyberProof-managed Microsoft Azure security services

This blog post is part of the Microsoft Intelligent Security Association MISA guest blog series. Learn more about MISA here. Security teams are struggling to reduce the time to detect and respond to threats due to the complexity and volume of alerts being generated from multiple security...

Bring your own LOLBin: Multi-stage, fileless Nodersok campaign delivers rare Node.js-based malware

We’ve discussed the challenges that fileless threats pose in security, and how Microsoft Defender Advanced Threat Protection Microsoft Defender ATP employs advanced strategies to defeat these sophisticated threats. Part of the slyness of fileless malware is their use of living-off-the-land...

Mini Shai Hulud: Compromised @antv npm packages enable CI/CD credential theft

In this article 1. Attack chain overview 1. Technical analysis 2. How GitHub took action to prevent further harm 2. Mitigation and protection guidance 1. Microsoft Defender XDR Detections 2. Microsoft Defender XDR Threat analytics 3. Advanced hunting 4. Indicators of Compromise IOC 3. References ...

Microsoft Security—detecting empires in the cloud

Microsoft consistently tracks the most advanced threat actors and evolving attack techniques. We use these findings to harden our products and platform and share them with the security community to help defenders everywhere better protect the planet. Recently, the Microsoft Threat Intelligence...

Data governance and retention in your Microsoft 365 tenant—a secure and highly capable solution

Data governance has relied on transferring data to a third-party for hosting an archive service. Emails, documents, chat logs, and third-party data Bloomberg, Facebook, LinkedIn, etc. must be saved in a way that it can’t be changed and won’t be lost. Data governance is part of IT at the enterpris...

From unstructured data to actionable intelligence: Using machine learning for threat intelligence

The security community has become proficient in using indicators of compromise IoC feeds for threat intelligence. Automated feeds have simplified the task of extracting and sharing IoCs. However, IoCs like IP addresses, domain names, and file hashes are in the lowest levels of the threat...

CISO series: Strengthen your organizational immune system with cybersecurity hygiene

One of the things I love about my job is the time I get to spend with security professionals, learning firsthand about the challenges of managing security strategy and implementation day to day. There are certain themes that come up over and over in these conversations. My colleague Ken Malcolmso...

Introducing Windows Defender System Guard runtime attestation

At Microsoft, we want users to be in control of their devices, including knowing the security health of these devices. If important security features should fail, users should be aware. Windows Defender System Guard runtime attestation, a new Windows platform security technology, fills this need...

The evolution of Microsoft Threat Protection, November update

At Ignite 2018, we announced Microsoft Threat Protection, a comprehensive, integrated solution securing the modern workplace across identities, endpoints, user data, cloud apps, and, infrastructure Figure 1. The foundation of the solution is the Microsoft Intelligent Security Graph, which...

Vulnerability in TikTok Android app could lead to one-click account hijacking

Microsoft discovered a high-severity vulnerability in the TikTok Android application, which could have allowed attackers to compromise users’ accounts with a single click. The vulnerability, which would have required several issues to be chained together to exploit, has been fixed and we did not...

Investigating identity threats in hybrid cloud environments

As the modern workplace transforms, the identity attack surface area is growing exponentially, across on-premises and cloud, spanning a multitude of endpoints and applications. Security Operations SecOps teams are challenged to monitor user activities, suspicious or otherwise, across all dimensio...

From cookie theft to BEC: Attackers use AiTM phishing sites as entry point to further financial fraud

A large-scale phishing campaign that used adversary-in-the-middle AiTM phishing sites stole passwords, hijacked a user’s sign-in session, and skipped the authentication process even if the user had enabled multifactor authentication MFA. The attackers then used the stolen credentials and session...

CISO series: Better cybersecurity requires a diverse and inclusive approach to AI and machine learning

Artificial Intelligence AI and machine learning have created lots of buzz with vendors. Being cast as the superheroes of technology is great for getting attention. But even Superman and Supergirl had their kryptonite. Could the lack of diversity and inclusiveness in the design teams and data type...

How to recover from a security breach

Experts estimate that ransomware attacks are up over 600 percent. For most companies, the issue isn’t if a cyberattack is going to happen, but when. Some security experts advise that the best way to recover from a security breach is to plan for it before it happens. Today we take you through:...

CISO series: Partnering with the C-Suite on cybersecurity

In my last blog, we looked at five communication techniques that can help engage business managers in the work of cybersecurity. This week, well look at how to use those techniques to bring the C-Suite into the conversation. Not too long ago, I was speaking with the CIO of a large company some...

Ovum recommends Microsoft security to safeguard your hybrid and multi cloud environments

According to a new Ovum report, "Azure Sentinel…positions Microsoft to be a force for change in a security information and events management SIEM market that is ripe for disruption at the moment." As enterprises migrate to the cloud, they’re increasingly operating on-premises and cloud environmen...

Two new Microsoft 365 offerings help address security and compliance needs

Today, were introducing two new offerings to help address the security and compliance needs in an age of increasingly sophisticated cybersecurity threats as well as complex information protection needs due to regulations like GDPR. The new Identity & Threat Protection and Information Protection &...

Cyberattacks against machine learning systems are more common than you think

Machine learning ML is making incredible transformations in critical areas such as finance, healthcare, and defense, impacting nearly every aspect of our lives. Many businesses, eager to capitalize on advancements in ML, have not scrutinized the security of their ML systems. Today, along with...

New Russia-affiliated actor Void Blizzard targets critical sectors for espionage

Executive summary: Void Blizzard is a new threat actor Microsoft Threat Intelligence has observed conducting espionage operations primarily targeting organizations that are important to Russian government objectives. These include organizations in government, defense, transportation, media, NGOs,...

Iran-linked DEV-0343 targeting defense, GIS, and maritime sectors

DEV-0343 is a new activity cluster that the Microsoft Threat Intelligence Center MSTIC first observed and began tracking in late July 2021. MSTIC has observed DEV-0343 conducting extensive password spraying against more than 250 Office 365 tenants, with a focus on US and Israeli defense technolog...

Executing on the vision of Microsoft Threat Protection

Over the last several months, we’ve provided regular updates on the rapid progress we’re making with Microsoft Threat Protection, which enables your organization to: Protect your assets with identity-driven security and powerful conditional access policies which ensure your assets are secured fro...

When prompts become shells: RCE vulnerabilities in AI agent frameworks

In this article 1. A representative case study: Semantic Kernel 2. CVE-2026-26030: In-Memory Vector Store 3. CVE-2026-25592: Arbitrary file write through SessionsPythonPlugin 4. The vulnerability 5. Attack chain overview 6. Defending the agentic edge 7. Not bugs, but developed by design 8. CTF...

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...

Microsoft finds new macOS vulnerability, Shrootless, that could bypass System Integrity Protection

Microsoft has discovered a vulnerability that could allow an attacker to bypass System Integrity Protection SIP in macOS and perform arbitrary operations on a device. We also found a similar technique that could allow an attacker to elevate their privileges to root an affected device. We shared...

Secure your journey to the cloud with free DMARC monitoring for Office 365

Not knowing who is sending email “from” your organization is an enormous problem for IT managers for two reasons. One problem is “shadow IT”—cloud services that employees have signed up for without IT oversight. Many of these services send mail—to employees, customers, or marketing prospects—whic...

Secure file storage

This is a blog 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 Collaborate Securely, the fifth...

Threat actor abuse of AI accelerates from tool to cyberattack surface

For the last year, one word has represented the conversation living at the intersection of AI and cybersecurity: speed. Speed matters, but it’s not the most important shift we are observing across the threat landscape today. Now, threat actors from nation states to cybercrime groups are embedding...

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...

Disrupting active exploitation of on-premises SharePoint vulnerabilities

July 23, 2025 update – Expanded analysis and threat intelligence from our continued monitoring of exploitation activity by Storm-2603 leading to the deployment of Warlock ransomware. Based on new information, we have updated the Attribution, Indicators of compromise, extended and clarified...

Protecting Android clipboard content from unintended exposure

Considering mobile users often use the clipboard to copy and paste sensitive information, like passwords or payment information, clipboard contents can be an attractive target for cyberattacks. Leveraging clipboards can enable attackers to collect target information and exfiltrate useful data...

Behavioral blocking and containment: Transforming optics into protection

In today’s threat landscape—overrun by fileless malware that live off the land, highly polymorphic threats that mutate faster than traditional solutions can keep up with, human-operated attacks that adapt to what adversaries find on compromised machines, and other sophisticated threats—behavioral...

Inside an AI‑enabled device code phishing campaign

In this article 1. Attack chain overview 2. Mitigation and protection guidance 3. Indicators of compromise IOC 4. References 5. Learn more Microsoft Defender Security Research has observed a widespread phishing campaign leveraging the Device Code Authentication flow to compromise organizational...

The evolution of Microsoft Threat Protection, June update

Since our announcement of Microsoft Threat Protection at Microsoft Ignite, our goal has been to execute and deliver on our promise of helping organizations protect themselves from today’s sophisticated and complex threat landscape. As we close out our fiscal year, we’ve continued progress on...

Lessons learned from the Microsoft SOC Part 2b: Career paths and readiness

The “Lessons learned from the Microsoft SOC” blog series is designed to share our approach and experience with security operations center SOC operations, so you can use what we learned to improve your SOC. The learnings in the series come primarily from Microsoft’s corporate IT security operation...

From edge appliance to enterprise compromise: Multi-stage Linux intrusion via F5 and Confluence

In this article 1. Attack chain overview 1. Initial access: Exploiting edge appliances 2. Discovery and reconnaissance 3. Lateral movement and identity compromise 2. Mitigation and protection guidance 1. Microsoft Defender XDR detections 2. Advanced hunting 3. Indicators of compromise IOC 4. MITR...

Uncursing the ncurses: Memory corruption vulnerabilities found in library

Microsoft has discovered a set of memory corruption vulnerabilities in a library called ncurses, which provides APIs that support text-based user interfaces TUI. Released in 1993, the ncurses library is commonly used by various programs on Portable Operating System Interface POSIX operating...

Top 5 use cases to help you make the most of your Cloud Access Security Broker

The number of apps and the flexibility for users to access them from anywhere continues to increase. This presents a challenge for IT departments in ensuring secure access and protecting the flow of critical data with a consistent set of controls. Cloud Access Security Brokers CASBs are a new...

New machine learning model sifts through the good to unearth the bad in evasive malware

We continuously harden machine learning protections against evasion and adversarial attacks. One of the latest innovations in our protection technology is the addition of a class of hardened malware detection machine learning models called monotonic models to Microsoft Defender ATP's Antivirus...

Microsoft gains strong customer and analyst momentum in the Cloud Access Security Brokers (CASB) market

After a strong year of product updates and innovations, were excited to so see that Microsoft jumped into the Challenger position in Gartners 2018 Magic Quadrant for Cloud Access Security Brokers CASB and solidified its leadership position in KuppingerColes 2018 Leadership Compass in the same...