Hackers Deploy AI Agents to Breach Thousands of Cloud Tenants
A China-aligned hacking group utilized an AI-driven framework to rapidly target thousands of Microsoft 365 accounts, achieving privileged access in a matter of hours.
By Isabella Morales ·
Cloud security is facing a new kind of pressure. A hacking group aligned with the Chinese state has shifted from manual break-ins to using artificial intelligence agents to infiltrate thousands of corporate cloud accounts. According to Microsoft, this group, identified as Storm-0940, utilized a system of LLM-driven agents to carry out an autonomous penetration test, allowing for automated scanning and password guessing without constant human supervision.
The scale of the operation is significant. Following unauthorized access to a multi-tenant application, the attackers attempted to log in to over 2,250 Microsoft 365 tenants. In some instances, the group managed to reach privileged access in under three hours from the moment they began targeting a specific organization. Microsoft noted that the activity did not stem from a compromise of its own systems or services.
The primary tool used was ARTEX, an open-source agentic AI penetration testing framework. This tool can operate around the clock with little human interaction, moving at a pace that leaves defenders with little time to detect and respond. Microsoft stated that the use of this technology sped up scanning, reconnaissance, password spraying, and OAuth application abuse.
Storm-0940 has been active since 2021 and is classified as a China-state aligned actor. The group's recent activity targeted a wide range of industries, including aerospace and defense, semiconductor, government, and think tanks, among a total of 14 listed sectors.
The technical details of the intrusion are complex. Automated password guessing, or password spraying, targeted 327 accounts across eight organizations, resulting in more than 151,000 failed logons with no successes. However, with control of the identities of multiple ConnectWise cloud apps, the attacking AI agents were able to sign in to customer tenants using those apps’ credentials.
Security firms have observed the group's methods closely. Huntress, a security firm, watched as an app added itself to the top administrator role in one tenant on Oct. 15. By Oct. 16, Huntress confirmed unauthorized sign-ins for 162 tenants, and a day later, almost 1,000 Entra tenants showed sign-in activity from the attacking IP.
The attack is linked to a broader supply chain issue involving ConnectWise. ConnectWise noted the unauthorized access and suspended Cloud Backup (formerly SkyKick), SaaS Security, and Cloud Management as a precaution. It has started a phased restoration with recovery expected to take several days and has no indicators to date that partner backup data was compromised.
Microsoft advises customers to keep affected app connections disabled until formal restoration instructions are issued and to review activity from this month where logs allow. It is still uncertain how the ConnectWise credentials were stolen or how many tenants were actually compromised.
Source: Tom's Hardware
