{"version":"1.0","type":"card","id":"54777167-ac54-4512-a58c-7041c26bfb56","url":"https://stacklist.com/card/54777167-ac54-4512-a58c-7041c26bfb56","title":"Securing AI agents: When AI tools move from reading to acting","source_url":"https://www.microsoft.com/en-us/security/blog/2026/06/30/securing-ai-agents-ai-tools-move-from-reading-acting/","note":"MCP tool poisoning turns trusted AI agents into a control plane for data loss. Learn how threat actors manipulate tool descriptions to trigger unauthorized actions, and how to detect, contain, and prevent it.","image":{"url":"https://ucarecdn.com/270078d0-d29d-40d1-8a3d-2acce7586b28/","alt":"Securing AI agents: When AI tools move from reading to acting","width":2000,"height":1124},"stack":{"id":"4f648364-9585-4a1c-8ecf-6de928fbc694","title":"Signals Served #018 - The Outcome Is the Product Now","url":"https://stacklist.com/c/finance/stack/4f648364-9585-4a1c-8ecf-6de928fbc694"},"created_at":"2026-07-21T20:16:02.413Z","updated_at":null,"aco":{"summary":"Microsoft Defender Experts observed increased ACR Stealer activity from late April 2026 to mid-June 2026, identifying two distinct intrusion chains across customer environments. The report also highlights the emerging risk of \"tool poisoning\" as AI agents evolve from passive reading to active execution capabilities.","tags":["acr-stealer","tool-poisoning","ai-agents","microsoft-defender","threat-activity","intrusion-chains","cybersecurity"],"key_entities":[{"name":"Microsoft","type":"organization","confidence":1},{"name":"ACR Stealer","type":"technology","confidence":1},{"name":"Microsoft Defender Experts","type":"technology","confidence":0.95},{"name":"Tool Poisoning","type":"concept","confidence":0.9},{"name":"AI Agents","type":"concept","confidence":0.85},{"name":"Intrusion Chains","type":"concept","confidence":0.8}],"classification":"analysis","language":"en","confidence":0.85,"provenance":{"model":"claude-opus-4-6","tool":"@stacklist/mcp-server@2.0.0","confidence":0.85,"timestamp":"2026-07-21T20:16:10.885Z"},"token_counts":{"approximate":58,"cl100k":48},"content_hash":"sha256:0d6f7c3348f623a846fa8184531a7fbb49569d0ad20972d32e3898ea03b8e2d8","acp_version":"0.2","body_available":true,"body_tokens":58,"visibility":"public","agent_accessible":true,"status":"final"},"_links":{"self":"/api/public/card/54777167-ac54-4512-a58c-7041c26bfb56.json","html":"https://stacklist.com/card/54777167-ac54-4512-a58c-7041c26bfb56","md":"/api/public/card/54777167-ac54-4512-a58c-7041c26bfb56.md","stack_json":"/api/public/stack/4f648364-9585-4a1c-8ecf-6de928fbc694.json"}}