Storm-0940 Leverages AI Framework for Rapid Microsoft 365 Infiltration

Storm-0940, a threat actor aligned with the Chinese state, executed a sophisticated supply chain attack against ConnectWise that leveraged automated artificial intelligence agents to compromise thousands of Microsoft 365 tenants. According to Microsoft, the group utilized ARTEX, an open-source framework designed for autonomous penetration testing, to accelerate reconnaissance and access attempts. This approach allowed the attackers to move with a speed and efficiency that traditional human-led operations rarely achieve, significantly compressing the time available for defenders to detect and respond to the intrusion.

The scale of the operation was substantial, with the actors attempting sign-ins at more than 2,250 distinct Microsoft 365 tenants. By using stolen credentials from ConnectWise applications, the AI agents authenticated directly as the apps without requiring interactive user logins. This method enabled privileged access in some instances within less than three hours of initial targeting. The speed was driven by the agents' ability to operate continuously with minimal human oversight, a capability that Microsoft notes leaves security teams with very little time to identify the breach.

In addition to the primary application abuse, the group conducted extensive password spraying campaigns. These automated attempts targeted 327 accounts across eight organizations, resulting in over 151,000 failed logon attempts with no successful breaches. On the peak day of October 11, the system generated 2,900 attempts per minute. Although nearly 98% of these activities resulted in account lockouts, the sheer volume indicates a highly aggressive strategy to find valid credentials or exploit misconfigurations.

The targeted sectors included aerospace and defense, semiconductors, government agencies, and think tanks. Microsoft clarified that the attack did not stem from a vulnerability in its own products or services. Instead, it relied on compromised third-party application identities. Once inside a tenant, the agents performed directory operations, changed application credentials, and modified privileged roles. In one specific case on October 15, security firm Huntress observed an application assigning itself to the top administrator role, a behavior that triggered specific alerts in Microsoft Defender.

The use of ARTEX represents a shift in how threat actors deploy AI, as the framework can integrate various large language models. While the developer of ARTEX has announced the project will become closed source and stop updates, other groups in different regions are already adopting similar technology. Recent reports have linked the framework to breaches at South Korean financial institutions, suggesting a broader trend of AI-driven cyber operations. For Southeast-based enterprises, this highlights the critical need to monitor third-party application permissions closely.

ConnectWise responded by suspending several services, including Cloud Backup and SaaS Security, as a precautionary measure. The company has begun a phased restoration process, with full recovery expected to take several days. While there are no current indicators that partner backup data was compromised, Microsoft advises customers to keep affected app connections disabled until formal instructions are issued. Organizations should review logs from this month to assess the extent of unauthorized activity within their own environments.

This incident underscores the evolving nature of supply chain risks in the cloud era. The integration of autonomous AI agents into the attack lifecycle means that detection and response times are shrinking. Companies must now assume that attackers can operate at a machine speed, requiring updated security controls that can handle high-volume, automated authentication events.