AI Agents Speed Up Hack Attack

Microsoft has detailed a sophisticated cyberattack that leverages artificial intelligence to move faster than traditional defenses can react. The incident highlights a growing trend where automated agents handle the heavy lifting of intrusion.

The attack, attributed to a China-state-aligned actor known as Storm-0940, targeted the ConnectWise platform. By exploiting unauthorized access to this multi-tenant application, the group used stolen credentials to sign in to over 2,250 Microsoft 365 tenants. These sign-ins occurred without interactive user login, allowing the attackers to operate behind the scenes. In some cases, the group achieved privileged access in less than three hours after initially targeting a victim.

The speed of the operation was driven by ARTEX, an open-source framework that uses large language models to run autonomous penetration tests. This tool allowed the attackers to perform reconnaissance, password guessing, and application abuse with minimal human interaction. At its peak on October 11, the automated password spraying campaign generated nearly 2,900 failed attempts per minute. While 98% of these were locked out, the use of specific application credentials allowed the agents to sign in to customer tenants rapidly, with more than 200 successful logins recorded in under four minutes.

Security firm Huntress observed specific behaviors in one tenant on October 15, noting that an application added itself to the top administrator role. This action triggered alerts and involved planting new secrets set to expire in 2028. By October 17, Huntress confirmed unauthorized sign-ins for nearly 1,000 tenants, with over 300 of those attempts succeeding. The systematic nature of the sweep, moving through tenants in sorted order just seconds apart, suggested the attackers were working from a pre-defined target list.

The group targeted industries including aerospace, defense, semiconductors, and government entities. Microsoft clarified that the attack did not stem from a vulnerability in its own systems but rather from the compromise of the ConnectWise application. The use of ARTEX is not unique to this group, as other actors in different regions have employed similar AI-driven tools. The developer of ARTEX has since announced the project will become closed source and will no longer receive updates.

ConnectWise has suspended several of its services as a precaution and has begun a phased restoration process. Recovery is expected to take several days, with no current indicators that partner backup data was stolen. Microsoft advises customers to keep affected app connections disabled until official restoration instructions are provided and to review recent activity logs for any signs of compromise.