Skip to main content


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

Friday, March 08, 2024

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 Intelligence investigation identified the threat actor as Midnight Blizzard, the Russian state-sponsored actor also known as NOBELIUM.

Microsoft addresses App Installer abuse

Thursday, December 28, 2023

Summary In recent months, Microsoft Threat Intelligence has observed threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the ms-appinstaller URI scheme. We have addressed and mitigated this malicious activity by turning off ms-appinstaller by default. Additionally, Microsoft has coordinated with Certificate Authorities to revoke the abused code signing certificates utilized by malware samples we have identified.

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

Tuesday, October 10, 2023

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 industry leader, Microsoft promptly opened an investigation and subsequently began working with industry partners for a coordinated disclosure and mitigation plan.

Announcing the Microsoft Machine Learning Membership Inference Competition (MICO)

Wednesday, November 16, 2022

We’re excited to announce the launch of a new competition focusing on the security and privacy of machine learning (ML) systems. Machine learning has already become a key enabler in many products and services, and this trend is likely to continue. It is therefore critical to understand the security and privacy guarantees provided by state-of-the-art ML algorithms – indeed this is one of Microsoft’s Responsible AI Principles.

New Research Paper: Pre-hijacking Attacks on Web User Accounts

Monday, May 23, 2022

In 2020, MSRC awarded two Identity Project Research Grants to support external researchers working to further strengthen the security of identity protocols and systems. Today we are pleased to release the results of the first of these projects. This research, led by independent security researcher Avinash Sudhodanan, investigated account pre-hijacking – a new class of attacks affecting websites and other online services.

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

Wednesday, February 19, 2014

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 and We will cover the following topics in this blog post:

Microsoft Releases Security Advisory 2914486

Wednesday, November 27, 2013

Today we released Security Advisory 2914486 regarding a local elevation of privilege (EoP) issue that affects customers using Microsoft Windows XP and Server 2003. Windows Vista and later are not affected by this local EoP issue. A member of the Microsoft Active Protections Program (MAPP) found this issue being used on systems compromised by a third-party remote code execution vulnerability.

MS13-051: Get Out of My Office!

Tuesday, June 11, 2013

MS13-051 addresses a security vulnerability in Microsoft Office 2003 and Office for Mac. Newer versions of Microsoft Office for Windows are not affected by this vulnerability, but the newest version of Office for Mac (2011) is affected. We have seen this vulnerability exploited in targeted 0day attacks in the wild. In this blog we’ll cover the following aspects:

New vulnerability affecting Internet Explorer 8 users

Saturday, December 29, 2012

Today, the MSRC released Security Advisory 2794220 alerting customers to limited, targeted attacks affecting customers using Internet Explorer 6, 7, and 8. Internet Explorer 9 and Internet Explorer 10 users are safe. More information about the vulnerability and exploit In this particular vulnerability, IE attempts to reference and use an object that had previously been freed.