Software giant Microsoft is grappling with a significant cybersecurity issue after it was revealed that Chinese-linked hackers have been exploiting vulnerabilities in SharePoint servers to target numerous organizations.

The scale and speed of these attacks, which leverage freshly discovered flaws, have raised considerable concern among cybersecurity experts and affected organizations.

Dutch startup Eye Security reported on Saturday that multiple waves of cyberattacks had targeted SharePoint file-sharing servers, prompting Microsoft to swiftly confirm the findings and release patches designed to safeguard systems.

According to Microsoft, the vulnerability in question allows hackers to retrieve credentials and gain unauthorized access to SharePoint servers located within users' facilities.

Notably, cloud-based versions of SharePoint are not affected by this issue.

Eye Security estimates that over 400 computer systems have been compromised thus far, with targets including government entities across Europe, the Middle East, and the United States.

Among these, it is reported that the US nuclear weapons agency has also been a victim.

Cybersecurity firm Palo Alto Networks has cautioned that on-premises SharePoint deployments—particularly within governmental bodies, educational institutions, healthcare providers, and large enterprises—are at an immediate risk.

Microsoft attributes these cyberattacks to several groups with alleged ties to the Chinese government, including Linen Typhoon and Violet Typhoon.

These organizations have been active for more than a decade and are known for engaging in intellectual property theft and espionage activities.

Microsoft has noted that while Storm-2603 is less well-documented, it is believed to be based in China and operates with similar objectives.

Damien Bancal, a cybersecurity specialist, recently discovered ready-to-use exploit code for this vulnerability on a popular website.

This incident highlights the ongoing efforts by sophisticated hacker groups—including those backed by nations like China—to target the Microsoft ecosystem through advanced cyberattacks.

In 2021, a Chinese hacker group known as Silk Typhoon launched attacks against tens of thousands of email servers using Microsoft Exchange software.

The widespread adoption of Microsoft products in both professional and personal settings makes them particularly attractive targets for hackers seeking to steal sensitive information or funds.

Shane Barney, head of information security at US-based Keeper, emphasizes that it is not Microsoft itself being targeted but rather its customers.

Rodrigue Le Bayon, the head of Orange Cyberdefense's computer emergency response team, further notes that while China is frequently implicated in such attacks, other nations also possess robust cyber capabilities.

This situation underscores the need for affected organizations to promptly apply security patches provided by Microsoft and to enhance their cybersecurity measures as a precaution against future attacks.

As tensions over cyber espionage continue to escalate on a global scale, companies like Microsoft find themselves at the forefront of efforts to protect sensitive information from unauthorized access.