In one American company's Microsoft account this month, a Teams app quietly made itself Global Administrator, the highest level of control in the system.
No employee approved it. The app was working for hackers aligned with China.
Microsoft disclosed on October 21 that a China-aligned hacking group it calls Storm-0940 broke into ConnectWise, a Tampa company whose software runs the IT for thousands of other businesses. The hackers got in through ConnectWise's Cloud Backup product. Then, Microsoft says, they used an AI-powered attack tool called ARTEX to go after ConnectWise's customers.
In multiple cases, it took under three hours to go from first targeting a company to holding privileged access inside it.
Burglars usually case a neighborhood one house at a time. These hackers found a faster way. They stole the property manager's master key.
ConnectWise doesn't sell to you directly. It sells to the IT outfits that look after small and mid-sized businesses, the people who keep the computers running at your accountant's office, your dentist and maybe your kid's school district. When ConnectWise's key got copied, every door it opened was suddenly at risk.
ARTEX is the burglar that doesn't need coffee. Microsoft calls it a multi-agent framework: AI software that can run an attack from scouting the network to stealing data with little human help. It scans, maps, guesses passwords and hijacks trusted apps. Security researchers have found versions set up to run on DeepSeek, the Chinese AI model that rattled Wall Street earlier this year.
"Agents are not constrained by factors affecting humans," Microsoft's researchers wrote. It doesn't sleep, doesn't take weekends and doesn't get tired of trying the next door.
At its peak, the campaign fired off 2,900 sign-in attempts a minute against more than 2,250 business accounts. A related password-spraying campaign logged more than 151,000 failed logins, 111,000 of them on October 11 alone. Forty-eight individual accounts took more than 1,000 hits each.
Most of those attempts bounced. Enough didn't.
Huntress, the security firm that first caught the activity, confirmed break-ins at 162 companies by October 16. It later found more than 300 tenants with successful logins. In about 50 of them, ConnectWise's own management apps gave themselves new powers. That's how a Teams app ended up as Global Administrator.
Two-factor authentication didn't help any of these companies. The hackers logged in as the ConnectWise app itself, so the security codes on employees' phones never came into play. A company could have done everything its IT guy told it to and still been exposed by the vendor it trusted.
"Nation-state actors are increasingly targeting the software supply chain," ConnectWise admitted in its advisory, "because one trusted connection can open the door to many organizations."
The target list reads like China's shopping list: aerospace and defense, government, the military, energy, financial services, semiconductors, law firms, manufacturing, chemicals, automotive, media, software and think tanks.
The scripted break-in attempts started October 13. ConnectWise went public October 16. On October 17, it shut off seven compromised app identities and pulled the plug on Cloud Backup, SaaS Security and Cloud Management. Businesses paying for cloud backup suddenly couldn't run backups, restore files or use their security tools. Service has been coming back in stages since.
ConnectWise says it has "no indication" the backup data itself was compromised. Microsoft says the hackers used the hijacked apps to get into customer accounts. Investigators are still sorting out what walked out the door.
China's embassy denied everything, the same way it has denied every hack ever traced back to it.
The last time a Chinese group got this deep, it was Salt Typhoon in 2024. That group burrowed into American telecom networks and went after phones connected to Donald Trump's and JD Vance's campaigns. Two years later, a China-aligned group is pointing AI at the companies that run everyone else's computers, and the time from first probe to full control now fits inside a lunch break.
They didn't have to pick 2,250 locks. They only had to copy one key.
