Microsoft warns of surge in ACR Stealer attacks
🛡️ Microsoft reports a marked increase in attacks leveraging ACR Stealer, an info-stealing MaaS that exfiltrates browser passwords, tokens, and sensitive documents from enterprise environments. Between late April and mid‑June, threat actors used social engineering (ClickFix), WebDAV servers, and mshta.exe to deliver obfuscated PowerShell loaders, Python-based installers, and in-memory payloads. The actor abuses GUID-based WebDAV paths, steganographic JPEGs, and public blockchains as dead-drop resolvers to mask activity and maintain C2 communications. Microsoft recommends filters, application control, and limiting access to unnecessary web resources to reduce exposure.
