Microsoft Says Chinese State-Backed Hackers Exploiting Flaws in Attacks

Asia Pacific|Microsoft Says Chinese State-Backed Hackers Exploiting Flaws in Attacks

Microsoft said that Chinese state-sponsored actors were exploiting vulnerabilities in one of its popular collaboration software products, SharePoint, which is used by U.S. government agencies and many companies worldwide.

Microsoft said in a notice on its security blog on Tuesday that it had identified at least two China-based groups linked to the Chinese government that it said had been taking advantage of security flaws in its SharePoint software. Such attacks aim to sneak into the computer systems of users.

Those groups, called Linen Typhoon and Violet Typhoon, were ones that Microsoft said it had been tracking for years, and which it said had been targeting organizations and personnel related to government, defense, human rights, higher education, media, and financial and health services in the United States, Europe and East Asia.

Microsoft said another actor, which it called Storm-2603, was also involved in the hacking campaign. It said it had “medium confidence” that Storm-2603 was a “China-based threat actor.”

The U.S. government’s Cybersecurity and Infrastructure Security Agency issued a notice that said it was aware of the hacking attack on SharePoint. It added that it had notified “critical infrastructure organizations” that were affected.

“While the scope and impact continue to be assessed,” the agency said, the vulnerabilities would enable “malicious actors to fully access SharePoint content, including file systems and internal configurations and execute code over the network.”

A Microsoft spokesperson wrote in an emailed response that the company had been “coordinating closely” with the Cybersecurity and Infrastructure Security Agency, the Department of Defense’s Cyber Defense Command and “key cybersecurity partners globally throughout our response.”

The Chinese Embassy in Washington did not immediately respond to a request for comment. China has routinely denied being behind cyberattacks and asserts that it is a victim of them.

Microsoft said in its blog post that investigations into other actors also using these exploits were still ongoing.

Eye Security, a cybersecurity firm, said that it had scanned more than 23,000 SharePoint servers worldwide, and discovered more than 400 systems had been actively compromised.

The cybersecurity firm also noted that the breaches could allow hackers to steal cryptographic keys that would allow them to impersonate users or services even after the server was patched. It said users would need to take further steps to protect their information.

Chinese hackers have shown growing sophistication in their ability to penetrate U.S. government systems, leaving American officials increasingly alarmed. During a breach of the U.S. telecommunications system last year, Chinese hackers were able to listen in on telephone conversations and read text messages, members of Congress said. The hack was considered so severe that former President Joseph R. Biden took it up directly with President Xi Jinping of China when they met in Peru in November.

In this latest breach, Microsoft said hackers had been using the software weaknesses to attempt, and gain, access to “target organizations” since as early as July 7. It issued security updates and urged users to install them immediately.

Microsoft revealed the vulnerabilities in SharePoint earlier this month, but at first patched them only partially. It said on July 19 that it was aware of active attacks trying to exploit those vulnerabilities.

Cybersecurity firms had said that they believed Chinese actors were among those attackers, even before Microsoft said so on Tuesday.

SharePoint helps organizations create websites and manage documents. It integrates with other Microsoft services such as Office, Teams and Outlook.

Microsoft said the vulnerabilities affected only on-premises SharePoint servers, meaning those managed by organizations on their own computer networks, and not those operated on Microsoft’s cloud.

Palo Alto Networks, a cybersecurity company, said in a post about the breach that on-premises servers “particularly within government, schools, health care (including hospitals) and large enterprise companies” were “at immediate risk.”

“A compromise in this situation doesn’t stay contained, it opens the door to the entire network,” the cybersecurity company said.