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Microsoft Uncovers Zero-Day Vulnerability Targeting US Tech Firms

7/25/2025

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Summary

Story summary

Microsoft revealed a zero-day vulnerability in SharePoint, exploited by hackers to deploy ransomware against US tech firms.
The vulnerability, dubbed "ToolShell," enables remote code execution and impacts over 400 SharePoint servers.
Microsoft has released patches and guidance, urging users to update promptly to reduce risks.
The threat actor, known as Storm-2603, is suspected to have ties to China and state-sponsored groups.

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Story summary

Microsoft revealed a zero-day vulnerability in SharePoint, exploited by hackers to deploy ransomware against US tech firms.
The vulnerability, dubbed "ToolShell," enables remote code execution and impacts over 400 SharePoint servers.
Microsoft has released patches and guidance, urging users to update promptly to reduce risks.
The threat actor, known as Storm-2603, is suspected to have ties to China and state-sponsored groups.