Published on: 2025-07-22

Intelligence Report: Microsoft pins on-prem SharePoint attacks on Chinese threat actors – Help Net Security

1. BLUF (Bottom Line Up Front)

Recent cyberattacks targeting on-premises Microsoft SharePoint servers have been attributed to Chinese threat actors, specifically identified as Linen Typhoon and Violet Typhoon. These attacks exploit vulnerabilities such as CVE-2023-29357 and CVE-2023-29358, posing significant risks to Western governments and critical infrastructure sectors. Immediate implementation of security patches and enhanced monitoring is recommended to mitigate these threats.

2. Detailed Analysis

The following structured analytic techniques have been applied to ensure methodological consistency:

Adversarial Threat Simulation

Simulated actions of the identified Chinese threat actors reveal potential vulnerabilities in SharePoint servers, emphasizing the need for robust defense mechanisms.

Indicators Development

Key indicators include exploitation attempts on specific CVEs and the deployment of custom webshells, which should be monitored for early detection.

Bayesian Scenario Modeling

Probabilistic models suggest a high likelihood of continued exploitation attempts, with potential escalation in sophistication and scope.

Network Influence Mapping

Mapping the influence of these threat actors highlights their capability to bypass security measures like MFA and SSO, indicating a well-coordinated effort.

3. Implications and Strategic Risks

The ongoing attacks underscore systemic vulnerabilities in critical infrastructure, with potential cascading effects on national security and economic stability. The exploitation of SharePoint servers could lead to data breaches, intellectual property theft, and disruption of government operations.

4. Recommendations and Outlook

• Immediately apply Microsoft’s security updates for SharePoint servers to close known vulnerabilities.
• Enhance monitoring and detection capabilities using tools like Microsoft Defender and implement robust antimalware solutions.
• Conduct regular security audits and penetration testing to identify and mitigate potential vulnerabilities.
• Scenario-based projections suggest that without intervention, the threat landscape will worsen, potentially leading to more sophisticated attacks.

5. Key Individuals and Entities

Linen Typhoon, Violet Typhoon, Check Point Research, SentinelOne, Palo Alto Networks, Trend Micro, Bitdefender.

6. Thematic Tags

national security threats, cybersecurity, counter-terrorism, regional focus