Critical Microsoft SharePoint Zero-Day Attack Hits 100+ Firms – How to Protect Your Server Now

Microsoft SharePoint zero-day vulnerability affected 100+ organizations and 8,000+ servers. Learn who was impacted and how to protect your server today.

A digital lock with a broken chain, symbolizing a critical zero-day vulnerability in a server rack, with a faint Microsoft SharePoint logo in the background.

Nearly one hundred organizations worldwide were hacked due to a SharePoint zero-day flaw that exposed global firms, affecting Microsoft SharePoint on-premises servers.

Key Points

- Introduction

- What Is the Microsoft SharePoint Hack.

-  Who Was Affected by This Microsoft Server Hack.

- Why This Hack Is Serious

- how to secure SharePoint server

- Final Thoughts / Conclusion

Continue reading: Mass attack spree hits Microsoft SharePoint exploits defect

During July 2025, a critical SharePoint vulnerability

applied to the SharePoint zero-day exploit impacts global companies — protection steps 

This cyber-attack compromised the security of about 100 organizations and potentially millions of others.

 Security researchers at Eye  Security and the Shadow server  Foundation discovered that it

 was exploited by hackers in order to access systems and install back doors and wait to gain long term access.

A cracked shield representing a compromised defense, with binary data flowing out of a stylized server icon, emphasizing the severity of a data breach.

Details of the SharePoint breach.Who Was Affected?

Researchers on the cyber security teams spotted an untouched vulnerability, called “Tool Shell” (CVE‑2025‑49706), in

 self‑managed SharePoint servers. 

Hackers took advantage of it beginning on July 18 acquiring remote code execution and total server control.

 Continue reading: SharePoint on premises security flaw hits servers worldwide 

Microsoft has outlined mitigation steps, including enabling AMSI and rotating machine keys, in its official advisory on disrupting active exploitation of SharePoint vulnerabilities

Who Was Affected by This Microsoft Server Hack?

So far, about hundreds of firms and organizations possibly impacted have confirmed breaches

 but targets span banks, healthcare, industrial firms, auditors, government bodies, and universities.

The FBI, U.K.’s NCSC, and other international agencies are now investigating.

A hacker's silhouette in front of a glowing green screen displaying code, with a subtle hint of a SharePoint interface, focusing on unauthorized access.

Why this Hack Is Serious 

- The exploit enabled thieves to retrieve cryptographic keys which implies that not only servers that have been patched are susceptible to hacking.

- More than thousands of servers SharePoint servers remain at risk online.

- Cyber security experts warn that installing patches won't get rid of existing backdoors—at that point a breach believed approach is basically fundamental.

How to safeguard your SharePoint environment from zero-day threats

1.Apply all Microsoft patches for SharePoint Server editions (2019, Subscription Edition, and in‑progress 2016 fix).

2.Disconnect vulnerable servers from the internet until they're secured.

3.Rotate cryptographic keys and credentials used by servers 

4.Presume breach and use response tools, such as hunting down unusual traffic, novel account logins, and backdoor installations.

5.Engage cyber security professionals for thorough post‑incident review.

A network diagram with a red alert symbol over a server node, indicating an active threat and disrupted connections due to an attack.

According to Reuters reports that roughly 100 organizations were impacted, researchers warn that simply patching might not eliminate all threats like embedded backdoors.

Final Thoughts

Hack of Microsoft server demonstrates the strength of a security flaw in a popular software.

The victims are close to 100 and the servers potentially threatened are over eight thousand systems: the correct choice is to act now. 

Patch your Microsoft SharePoint servers, investigate systems that have been behaving suspiciously and act as though a compromise has already occurred. 

This campaign should be a wake-up call, to be more guarded, swift and vigilant.

 - Is your SharePoint server patched? It only takes 15 minutes to secure it.

A padlock icon with a glowing red 'X' over it, superimposed on a blurred background of office workers, representing immediate danger to businesses.

- Need help? Contact a trusted cyber security firm immediately.

-  Stay informed! Share this article with your IT team and subscribe to receive future security alerts.

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