Microsoft Security Blog
Your source for the latest in cybersecurity
Featured Posts
From guidance to action: Security fundamentals that materially reduce risk
AI has made fundamental changes to the operating environment for cybersecurity.
Improving email security outcomes with real-world Microsoft Defender insights
The latest email security benchmarking reports show strong Microsoft Defender performance across pre-delivery and post-delivery scenarios and reveal where threats and defenses continue to evolve.
What’s new in Microsoft Security: August 2026
This month’s updates provide new capabilities to help organizations gain insights into agent activity, expand security coverage across supported environments, and enhance security management across their environments.
Advance Zero Trust for AI: New tools and guidance to secure AI agents and DevSecOps
Microsoft expands its Zero Trust for AI strategy to enhance security for AI and DevSecOps environments with new tools and guidance.
Threat intelligence
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Protecting organizations from AI-assisted executive impersonation and invoice fraud
Microsoft examines an AI-assisted business email compromise campaign that used executive impersonation and fake invoices to target finance teams with ACH payment fraud. -
Passkey-themed social engineering leads to identity and cloud compromise
Passkey-themed social engineering is being used to compromise identities and enable broader cloud attacks. -
ASCII smuggling crosses over from AI prompt injection to phishing evasion
Invisible Unicode characters popularized for hiding instructions from AI models are now being used to obfuscate words before email filters parse them.
Stay ahead of threats
Get expert insights, threat intelligence, and the latest cybersecurity reports from Security Insider.
AI and machine learning
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From guidance to action: Security fundamentals that materially reduce risk
AI has made fundamental changes to the operating environment for cybersecurity. -
Improving email security outcomes with real-world Microsoft Defender insights
The latest email security benchmarking reports show strong Microsoft Defender performance across pre-delivery and post-delivery scenarios and reveal where threats and defenses continue to evolve. -
Protecting organizations from AI-assisted executive impersonation and invoice fraud
Microsoft examines an AI-assisted business email compromise campaign that used executive impersonation and fake invoices to target finance teams with ACH payment fraud.
Modernize your security operations center
Confidently secure your multicloud, multiplatform environment with Microsoft Sentinel – a cloud-native security information and event management (SIEM) solution.
Latest posts
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From guidance to action: Security fundamentals that materially reduce risk
AI has made fundamental changes to the operating environment for cybersecurity. -
Improving email security outcomes with real-world Microsoft Defender insights
The latest email security benchmarking reports show strong Microsoft Defender performance across pre-delivery and post-delivery scenarios and reveal where threats and defenses continue to evolve. -
Protecting organizations from AI-assisted executive impersonation and invoice fraud
Microsoft examines an AI-assisted business email compromise campaign that used executive impersonation and fake invoices to target finance teams with ACH payment fraud. -
Detect and disrupt AI-themed attacks with Microsoft Defender
See how Microsoft Defender detects and disrupts AI-themed phishing, malware, and multi-stage attacks across the attack chain. -
Threat matrix: Mapping threats across cloud web applications
Microsoft introduces the Cloud Web Applications Threat Matrix, a MITRE ATT&CK-aligned framework that helps defenders understand, prioritize, and mitigate threats to cloud-hosted web apps and serverless platforms. -
Passkey-themed social engineering leads to identity and cloud compromise
Passkey-themed social engineering is being used to compromise identities and enable broader cloud attacks.