Microsoft: China-state-aligned Storm-0940 used the ARTEX agentic AI framework against hundreds of organizations and in the ConnectWise supply-chain breach, hitting 2,250+ tenants at 2,900 sign-ins a minute

Why it matters

【Key points】

On Oct 21 Microsoft Threat Intelligence said Storm-0940, a China-state-aligned actor active since 2021, has used the open-source agentic pentest framework ARTEX since at least September 2026 to automate attacks on hundreds of organizations. Microsoft attributes the recent ConnectWise Cloud Backup supply-chain compromise to the group.

In several cases it went from first targeting to privileged cloud access in under three hours. After seizing several ConnectWise app identities, ARTEX agents tried to sign in to more than 2,250 downstream tenants, at a peak of 2,900 attempts a minute. In some tenants they changed credentials and privileged roles via Microsoft Graph. A password spray on Oct 10–14 from the same 144.172.64.x range produced 151,000+ failed logons and no successes.

Microsoft says no Microsoft vulnerability was involved and that sign-ins don't prove data theft. The number of victims is unknown.

【Verifiable】

https://www.microsoft.com/en-us/security/blog/2026/10/21/storm-0940-uses-artex-agentic-ai-connectwise-supply-chain-compromise/

https://x.com/MsftSecIntel/status/2112975078266716390

https://cyberscoop.com/microsoft-attributes-connectwise-supply-chain-attack-china-storm-0940/

Earlier: https://www.crowdstrike.com/en-us/blog/unknown-threat-actor-uses-artex-to-target-south-korean-finance/

【Our read】

1. Two weeks after CrowdStrike tied ARTEX to one attacker's Korean bank breaches, Microsoft links it to a state-aligned group running a long campaign. Going closed source did not take back code that was already out.

2. The techniques are old (password spraying, OAuth app abuse). AI changed the speed and scale, leaving human defenders almost no time to react.

3. High-privilege multi-tenant SaaS apps are now the weak link. Because ARTEX works with any model, restricting one vendor's model helps little. Expect the focus to shift to detecting agent behavior and to automated defense.