Bitdefender links 3AM ransomware to AI assisted school attack

Bitdefender’s investigation has found that a UK school estate was compromised by the 3AM ransomware group using a hybrid human-AI approach. The incident took place from 10 to 19 September 2026, during which attackers encrypted 37 machines and established domain trust across the compromised estate to reach other schools.

Bitdefender described this as the first European case documenting a hybrid operation of this kind, with a human operator at the keyboard performing some steps while an AI model handled others, suggesting the tactic could become more common in 2027.

The attack chain, attributed to a 3AM affiliate operating a Rust-based encryptor first seen in February 2023, began with access to backup infrastructure credentials and decryption via the Windows Data Protection API. From 12–13 September, the threat actor tested connections to other hosts via WMI using stolen admin credentials, with outputs read by either a human or AI agent to guide subsequent commands. The sequence involved PowerShell and then wmic, with rapid command rewrites indicating AI-driven retries.

By 14 September, the attacker pursued persistence using Mimikatz and created two backdoor domain-administrator accounts. They exfiltrated 40 financially related files to a C2 endpoint, and on 19 September joined three AD domains with two-way trusts, enabling access across the estate to 50 machines. The operation culminated in decrypting 37 of the accessed machines, after attempts to remove EDR tools.

Bitdefender notes the hybrid model’s “mechanical” tasks and the altered incident traces it creates, and outlines defensive steps: segment admin accounts across domains, protect backup infrastructure, restrict remote execution, block interpreters, and deploy an endpoint agent on every machine.