Congratulations to the Top MSRC 2024 Q2 Security Researchers!

Congratulations to all the researchers recognized in this quarter’s Microsoft Researcher Recognition Program leaderboard! Thank you to everyone for your hard work and continued partnership to secure customers. The top three researchers of the 2024 Q2 Security Researcher Leaderboard are Yuki Chen,...

BlueHat October 2023 Call for Papers is Now Open!

As you may have seen on social media, the next BlueHat conference will be October 11 – 12, 2023, on Microsoft’s Redmond campus in Washington state, USA. The Call for Papers CFP is now open through August 18, 2023. The BlueHat community is a unique blend of security researchers and responders from...

Mitigation for Azure Storage SDK Client-Side Encryption Padding Oracle Vulnerability

Summary Google informed Microsoft under Coordinated Vulnerability Disclosure CVD of a padding oracle vulnerability that may affect customers using Azure Storage SDK for Python, .NET, Java client-side encryption CVE-2022-30187. To mitigate this vulnerability, we released a new General Availability...

Cyber threat activity in Ukraine: analysis and resources

UPDATE 02 MAR 2022: See Updated malware details and Microsoft security product detections below for additional insights and protections specific to the evolving threats we have identified impacting organizations with ties to Ukraine. Microsoft has been monitoring escalating cyber activity in...

Announcing the Microsoft Identity Research Project Grant

We are excited to announce the Microsoft Identity Research Project Grant a new opportunity in partnership with the security community to help protect Microsoft customers. This project grant awards up to $75,000 USD for approved research proposals that improve the security of the Microsoft Identit...

BlueHat Shanghai 2019 Call for Papers is Now Open!

We know security experts with diverse skills and experiences are found around the world. This year, the BlueHat Security Conference is coming to Shanghai! BlueHat Shanghai 2019 will take place on May 29-30 at W Shanghai - The Bund. We want to provide a venue for security researchers to come...

The MSRC 2017 list of “Top 100” security researchers

Security researchers play an essential role in Microsoft’s security strategy and are key to community-based defense. To show our appreciation for their hard work and partnership, each year at BlackHat North America, the Microsoft Security Response Center highlights contributions of these...

Congratulations to the top MSRC 2025 Q4 security researchers!

Congratulations to all the researchers recognized in this quarter’sMicrosoft Researcher Recognition Programleaderboard! Thank you to everyone for your hard work and continued partnership to secure customers...

Journey Down Under: How Rocco Became Australia’s Premier Hacker

Fun facts about Rocco Calvi @TecR0c: Microsoft MVR: Rocco is a 2023 Microsoft Most Valuable Researcher. Fitness fanatic: Inspired by old-school body building and countless hours of chopping and carrying wood in the mountains during his youth, Rocco remains a fitness enthusiast, setting himself...

New MSRC Blog Site

We are excited to announce the release of the new Microsoft Security Response Center MSRC blog site. Please visit msrc.microsoft.com/blog/starting February 9th, 2023, for all past and future MSRC blog content. In addition to the new URL, we have refreshed the site with a new look and improved sit...

Windows DNS サーバーの脆弱性情報 CVE-2020-1350 に関する注意喚起

本記事は、「July 2020 Security Update: CVE-2020-1350 Vulnerability in Windows Domain Name System DNS Server」の日本語抄訳です。 本日、脆弱性情報 CVE-2020-1350 を公開し...

Azure Sphere Security Research Challenge Now Open

The Azure Sphere Security Research Challenge is an expansion of Azure Security Lab, announced at Black Hat in August 2019. At that time, a select group of talented researchers was invited to come and do their worst, emulating criminal hackers in a customer-safe cloud environment. This new researc...

Time for day 2 of briefings at BlueHat Seattle!

We hope you enjoyed the first day of our BlueHat briefings and the Bytes of BlueHat reception in our glamping tent complete with toasted marshmallows. Yesterday, we learned a lot about how XboxOne hardware security has advanced the state of hardware security elsewhere, we heard some surprising...

CVE-2013-3893: Fix it workaround available

Today, we released a Fix it workaround tool to address a new IE vulnerability that had been actively exploited in extremely limited, targeted attacks. This Fix it makes a minor modification to mshtml.dll when it is loaded in memory to address the vulnerability. This Fix it workaround tool is link...

Congratulations to the MSRC 2026 Most Valuable Security Researchers

We are grateful to every security researcher who partnered with us over the past year. Through their reports and collaboration, they helped us identify and address vulnerabilities across our products and services...

Mitigating NTLM Relay Attacks by Default

Introduction In February 2024, we released an update to Exchange Server which contained a security improvement referenced by CVE-2024-21410 that enabled Extended Protection for Authentication EPA by default for new and existing installs of Exchange 2019. While we’re currently unaware of any activ...

Announcing BlueHat 2024: Call for Papers now open

The 23rd edition of Microsoft’s BlueHat security conference will be hosted by the Microsoft Security Response Center MSRC at the Redmond, WA corporate campus, October 29 and 30, 2024. BlueHat brings together security researchers and responders from both inside and outside of Microsoft, who come...

Embracing innovation: Derrick’s transition from banking to Microsoft’s Threat Intelligence team

Meet Derrick, a Senior Program Manager on the Operational Threat Intelligence team at Microsoft. Derrick’s role involves understanding and roadmapping the complete set of tools that Threat Intel analysts use to collect, analyze, process, and disseminate threat intelligence across Microsoft...

Azure AD アプリケーションにおける特権昇格の潜在的なリスクについて

本ブログは、Potential Risk of Privilege Escalation in Azure AD Applications の抄訳版です。最新の情報は原文を参照してください。 概要...

Congratulations to the Top MSRC 2022 Q2 Security Researchers!

Congratulations to all the researchers recognized in this quarter’s Microsoft Researcher Recognition Program leaderboard! Thank you to everyone for your hard work and continued partnership to secure customers. The top three researchers of the 2022 Q2 Security Researcher Leaderboard are: Yuki Chen...

Clarifying the behavior of mandatory ASLR

Last week, the CERT/CC published an advisory describing some unexpected behavior they observed when enabling system-wide mandatory Address Space Layout Randomization ASLR using Windows Defender Exploit Guard WDEG and EMET on Windows 8 and above. In this blog post, we will explain the configuratio...

Fix it tool available to block Internet Explorer attacks leveraging CVE-2014-0322

Today, we released Security Advisory 2934088 to provide guidance to customers concerned about a new vulnerability found in Internet Explorer versions 9 and 10. This vulnerability has been exploited in limited, targeted attacks against Internet Explorer 10 users browsing to www.vfw.org and...

Zero Day Quest: Join the largest hacking event with up to $5 million in total bounty awards

Last year, we announced the largest hacking event in history: Zero Day Quest, with up to $4 million in bounty awards. The response from the global security community was incredible and helped improve security for our customers and partners. This year, Zero Day Quest is back with even more potenti...

Congratulations to the Top MSRC 2024 Q3 Security Researchers!

Congratulations to all the researchers recognized in this quarter’s Microsoft Researcher Recognition Program leaderboard! Thank you to everyone for your hard work and continued partnership to secure customers. The top three researchers of the 2024 Q3 Security Researcher Leaderboard are wkai,...

Update on Microsoft Actions Following Attack by Nation State Actor Midnight Blizzard

This blog provides an update on the nation-state attack that was detected by the Microsoft Security Team on January 12, 2024. As we shared, on January 19, the security team detected this attack on our corporate email systems and immediately activated our response process. The Microsoft Threat...

Microsoft boosts its Microsoft 365 Insider Builds on Windows Bounty Program with higher awards and an expanded scope

Starting today, we are doubling the maximum bounty award for the Microsoft 365 Insider Bug Bounty Program to $30,000 USD for high impact scenarios, such as unauthenticated non-sandboxed code execution with no user interaction. We are also expanding the scope of our bounty program to include more...

Microsoft Response to Layer 7 Distributed Denial of Service (DDoS) Attacks

Summary Summary Beginning in early June 2023, Microsoft identified surges in traffic against some services that temporarily impacted availability. Microsoft promptly opened an investigation and subsequently began tracking ongoing DDoS activity by the threat actor that Microsoft tracks as...

Microsoft Mitigates Vulnerability in Jupyter Notebooks for Azure Cosmos DB

Summary Microsoft recently fixed an authentication bypass vulnerability in Jupyter Notebooks for Azure Cosmos DB currently in preview reported by Orca Security. Customers not using Jupyter Notebooks 99.8% of Azure Cosmos DB customers do NOT use Jupyter notebooks were not susceptible to this...

Investigation Regarding Misconfigured Microsoft Storage Location

October 28, 2022 update:Added a Customer FAQ section. Summary Security researchers at SOCRadar informed Microsoft on September 24, 2022, of a misconfigured Microsoft endpoint. This misconfiguration resulted in the potential for unauthenticated access to some business transaction data correspondin...

Defense-in-Depth Updates for Azure Identity libraries and Azure Key Vault libraries within Azure SDK plus Best Practice Implementation Guidance

Summary Today, Microsoft released new versions of the Azure Key Vault libraries and Azure Identity libraries as part of the Azure Software Development Kit SDK that includes defense-in-depth feature improvements. We also published best practice guidance to help protect applications and services th...

CVE-2022-23278 Microsoft Defender for Endpointのなりますましの脆弱性に関するガイダンス

本ブログは、Guidance for CVE-2022-23278 spoofing in Microsoft Defender for Endpoint の抄訳版です。最新の情報は原文を参照してください。 マイク...

An Armful of CHERIs

Today, Arm announced that the first silicon supporting the Morello prototype architecture, a research project led by Arm, Microsoft, University of Cambridge and others, is now available on a limited run of demonstration boards, which are being shipped from today to industry partners for testing...

Analysis and mitigation of speculative store bypass (CVE-2018-3639)

In January, 2018, Microsoft published an advisory and security updates for a new class of hardware vulnerabilities involving speculative execution side channels known as Spectre and Meltdown. In this blog post, we will provide a technical analysis of an additional subclass of speculative executio...

Congratulations to the Top MSRC 2025 Q1 Security Researchers!

Congratulations to all the researchers recognized in this quarter’s Microsoft Researcher Recognition Program leaderboard! Thank you to everyone for your hard work and continued partnership to secure customers. The top three researchers of the 2025 Q1 Security Researcher Leaderboard are 0x140ce,...

Microsoft Response to Distributed Denial of Service (DDoS) Attacks against HTTP/2

Summary Beginning in September 2023, Microsoft was notified by industry partners about a newly identified Distributed Denial-of-Service DDoS attack technique being used in the wild targeting HTTP/2 protocol. This vulnerability CVE-2023-44487 impacts any internet exposed HTTP/2 endpoints. As an...

Breaking Barriers: Aditi’s Journey Through Sight Loss to Microsoft AI Innovator

Facts about Aditi Shah: Tools she uses: Aditi’s main tool is JAWS, a screen reader from Freedom Scientific, which she touts as the best in the market. This tool has made her digital life more manageable, enabling her to perform almost any task independently. Aditi also uses Seeing AI, a Microsoft...

Potential Risk of Privilege Escalation in Azure AD Applications

Summary Microsoft has developed mitigations for an insecure anti-pattern used in Azure AD AAD applications highlighted by Descope, and reported to Microsoft, where use of the email claim from access tokens for authorization can lead to an escalation of privilege. An attacker can falsify the email...

Hey Yara, find some vulnerabilities

Intro Intro Finding vulnerabilities in software is no easy task by itself. Doing this at cloud scale is very challenging to perform manually, and we use tools to help us identify patterns or vulnerability signatures. Yara is one of those tools. Yara is a very popular tool with Blue teams, malware...

Azure ADを使用するマルチテナント アプリケーションの承認に関する構成ミスの可能性に関するガイダンス

本ブログは、Guidance on Potential Misconfiguration of Authorization of Multi-Tenant Applications that use Azure AD の抄訳版です。最新の情報は原文を参照してください...

セキュリティ更新プログラムガイド CVRF API での CBL-Mariner CVE の 公開について

本ブログは、Publishing CBL-Mariner CVEs on the Security Update Guide CVRF API の抄訳版です。最新の情報は原文を参照してください。...

Security Update Guide Improvement – Representing Hotpatch Updates

Today we are updating the way Microsoft Security Update Guide SUG represents the Windows Hotpatch feature to make it easier for users to identify the hotpatch and security updates. Hotpatching was introduced a year ago as a new way to install updates on supported Windows Server Azure Edition...

Hunting for Cobalt Strike: Mining and plotting for fun and profit

Introduction Cobalt Strike is a commercial Command and Control framework built by Helpsystems. You can find out more about Cobalt Strike on the MITRE ATT&CK page. But it can also be used by real adversaries. In this post we describe how to use RiskIQ and other Microsoft technologies to see if you...

A Man of Action: Meet Callum Carney

Hidden Talents: He was a competitive swimmer for many years. Instrument of Choice: His fingers were made for the keyboard, but he used to play the trumpet. 5 pieces of entertainment for the rest of his life: The Office, World War Z, The Matrix, Breaking Bad, The Thick of It. Favorite non-profit:...

Researcher Spotlight: Hector Peralta’s Evolution from Popcorn Server to the MSRC Leaderboards

“The bug bounty literally changed my life. Before this, I had nothing.” Coolest thing he purchased: His first vehicle! Best gift to give: Buying his nephew gaming accessories. Favorite Hacking Companion: His two cats. They’re always by his side when he is working late. Origin of his Hacker name:...

An Armful of CHERIs

Today, Arm announced that the first silicon supporting the Morello prototype architecture, a research project led by Arm, Microsoft, University of Cambridge and others, is now available on a limited run of demonstration boards, which are being shipped from today to industry partners for testing...

Solving Uninitialized Stack Memory on Windows

This blog post outlines the work that Microsoft is doing to eliminate uninitialized stack memory vulnerabilities from Windows and why we’re on this path. This blog post will be broken down into a few parts that folks can jump to: Uninitialized Memory Background Potential Solutions to Uninitialize...

Announcing MSRC 2019 Q4 Security Researcher Leaderboard

Following the first Security Researcher Quarterly Leaderboard we published in October 2019, we are excited to announce the MSRC Q4 2019 Security Researcher Leaderboard, which shows the top contributing researchers for the last quarter. In each quarterly leaderboard, we recognize the security...

Understanding CVE-2025-55315: What CISOs, security engineers, and sysadmins should know

On October 14, 2025, Microsoft released a security update addressingCVE-2025-55315, a vulnerability in ASP.NET Core that allows HTTP request smuggling. While request smuggling is a known technique, this security update addresses a scenario with a high CVSS score to help encourage mitigation actio...

Reflecting on 20 years of Patch Tuesday

This year is a landmark moment for Microsoft as we observe the 20th anniversary of Patch Tuesday updates, an initiative that has become a cornerstone of the IT world’s approach to cybersecurity. Originating from the Trustworthy Computing memo by Bill Gates in 2002, our unwavering commitment to...

Results of Major Technical Investigations for Storm-0558 Key Acquisition

March 12, 2024 update As part of our continued commitment to transparency and trust outlined in Microsoft’s Secure Future Initiative, we are providing further information as it relates to our ongoing investigation. This new information does not change the customer guidance we previously shared, n...