Ethical Hacking News
Microsoft has linked a recent breach to a China-linked group using an AI pentesting tool called ARTEX. The breach affected over 2,250 Microsoft 365 tenants, and it is believed that the group used ARTEX to carry out the attacks. The report highlights the speed and scale of the attacks, which were made possible by the use of ARTEX. The breach is another example of how threat actors are integrating agentic AI into existing offensive security workflows to scale their operations exponentially.
Storm-0940, a China-linked group, is responsible for the ConnectWise Cloud Backup supply chain compromise affecting over 2,250 Microsoft 365 tenants. ARTEX, an AI-powered penetration testing framework, was used by Storm-0940 to carry out the attacks. The attacks exploited stolen ConnectWise credentials and gained access to customer Microsoft 365 environments without requiring user interaction. The attackers obtained privileged access to an organization's cloud infrastructure within less than three hours of initial targeting. Microsoft assesses that Storm-0940's use of ARTEX increased the scale of their attacks. The attackers used a password spraying attack between October 10 and 14, resulting in over 151,000 failed login attempts. After the breach became public, the attackers switched to a different attack method using stolen credentials to log into customer Microsoft 365 environments. Follow-on activity included directory reconnaissance, modifying application credentials, and attempting changes to identities and groups. Persistence mechanisms remain a concern for defenders, even if the initial breach is addressed.
Microsoft has recently published a detailed technical report that names a China-linked group, known as Storm-0940, as the actor behind the ConnectWise Cloud Backup supply chain compromise. The breach affected over 2,250 Microsoft 365 tenants, and it is believed that the group used an open-source AI-driven penetration testing framework called ARTEX to carry out the attacks.
ARTEX is an AI-powered tool that can be used to plan and carry out tasks, and it is not limited to being used by Storm-0940. Researchers at Zscaler and Recorded Future have also found instances of Chinese-speaking groups using the same framework to target South Korean financial institutions.
The attacks carried out by Storm-0940 were highly sophisticated and exploited stolen ConnectWise credentials to gain access to customer Microsoft 365 environments. The group used applications that already had permission to access their targets, allowing them to enter customer environments without requiring users to sign in interactively.
In some cases, the attackers were able to obtain privileged access to an organization's cloud infrastructure within less than three hours of initial targeting. This highlights the speed and scale of the attacks carried out by Storm-0940, which were made possible by the use of ARTEX.
Microsoft assesses that Storm-0940 was responsible for the recently disclosed ConnectWise supply chain compromise of a multi-tenant application. The group has been active since 2021 and has historically relied on password spraying and OAuth application abuse to get into Microsoft 365 environments. Adding ARTEX changed the scale of what they could do.
The report by Microsoft also highlights the speed point of the attacks carried out by Storm-0940. Agents do not take weekends, do not sleep, and can run multiple attack paths simultaneously. This demonstrates how threat actors are integrating agentic AI into existing offensive security workflows and allows them to scale their operations exponentially.
The attackers used a password spraying attack between October 10 and 14, which resulted in more than 151,000 failed login attempts against 327 accounts at eight organizations. Activity peaked on October 11, with 2,900 failed attempts per minute. Forty-eight accounts each received more than 1,000 failed attempts. None of these attempts succeeded.
However, after the ConnectWise breach became public on October 15, the AI agents stopped trying passwords and switched to a different attack method. By then, Storm-0940 had obtained the credentials of several ConnectWise cloud application accounts. The agents used these credentials to log directly into customer Microsoft 365 environments.
In a subset of environments where authentication succeeded, the agents did not stop there. They moved into Microsoft Graph and ran directory reconnaissance, modified application credentials to establish persistence, and attempted changes to identities, groups, and privileged roles. Microsoft identified multiple customer environments with evidence of this follow-on activity.
The persistence mechanism is the part defenders need to act on now, even if they've already disabled the ConnectWise connections. An attacker who added their own credentials to a trusted application before you revoked access still has a working key. Reviewing all service principal credential additions since at least October 1 is the right starting point, not October 15 when the public breach was announced.
Related Information:
https://www.ethicalhackingnews.com/articles/Microsoft-Links-ConnectWise-Breach-to-China-Linked-Group-Using-AI-Pentesting-Tool-ARTEX-ehn.shtml
https://securityaffairs.com/201501/apt/microsoft-links-connectwise-breach-to-china-linked-group-using-ai-pentesting-tool-artex.html
Published: Thu Oct 22 17:09:20 2026 by llama3.2 3B Q4_K_M
