ConnectWise makes software that IT firms use to look after their customers' computers and accounts, and one of its products backs up companies' Microsoft 365 data. Attackers aligned with the Chinese state broke into that backup service and took the keys it uses to sign in to its customers' Microsoft accounts. They then pointed an open-source AI program called ARTEX at those accounts, and it tried to get into more than 2,250 companies. ConnectWise switched the service off, and backups stopped running and could not be restored while it investigated.
An app's key never asks for a login code
When a company lets a backup app into its Microsoft 365, the vendor's app holds its own key and uses it to sign in by itself, with nobody there to type a password. That is what makes the app useful. It is also why a login code on a phone does nothing here: whoever holds the key signs in as the app, and there is no person to ask. Microsoft saw the attackers get in this way without any user signing in, read what the app could read, and in some places try to give themselves wider rights.
The machine made each extra company almost free to try
Breaking into a company used to cost a skilled person hours, so criminals picked their targets. ARTEX takes a goal and does the work itself: one agent chooses the next step, others run the scanning and sign-in tools, and every result goes into a shared map of what was found, as Wiz's analysis of the tool describes.
Pointed at the stolen keys, it made about 2,900 sign-in tries a minute, which is nearly 48 every second. In some attacks by the same group, less than three hours passed between picking a company and holding top-level access to its cloud accounts. Alerts fire in a flood like that, but the attacker is through before anyone has read them.
Most tries failed. Still, when each extra company costs almost nothing, a success rate of one in a hundred means more than 20 companies from the effort that once went into one.
Your exposure is the list of apps you approved
We wrote earlier about how AI attackers try every side door, whatever the size of the target. This is a side door many companies did not know they had.
Take a 40-person accounting firm whose IT provider set up a backup app three years ago. Someone clicked approve, the app can read every mailbox and file, and nobody remembers it. The firm did nothing wrong that day, and it would be one of the companies the attackers tried if that vendor were the one that lost its keys.
Checking takes about an hour. In the Microsoft 365 admin area, open the list of enterprise applications. For each app, ask who uses it, what it can read, and when it last signed in. An app nobody can answer for should go. For companies that used ConnectWise's backup, Microsoft's advice is to look even where the app is no longer in use, to keep the ConnectWise apps disabled, and to save the logs before deleting anything.
Anyone who bought backup for safety learned a second thing. While the service was off, there was no backup and no restore, so the protection stopped at the moment it was needed. A second copy that does not depend on the same vendor's connection is cheap insurance.
Each approved app ties your company's safety to the vendor's worst day, and AI has cut the time you get to react on that day to hours. What you control is how much each key can open, so when an app asks for access to every mailbox, ask whether it needs only one.