Overview

• The FTC confirmed receipt of Sen. Ron Wyden’s Sept. 10 request to investigate Microsoft for alleged “gross cybersecurity negligence.”
• Wyden’s office said the Ascension breach started when a contractor clicked a malicious Bing search result in Edge, leading to an Active Directory compromise and ransomware spread.
• The attackers allegedly used Kerberoasting against RC4-based Kerberos tickets, a weakness federal agencies have warned has been exploited in health care and by foreign actors.
• Ascension reported exposure of data for about 5.6 million patients and temporary disruptions to hospital operations during the 2024 incident.
• Microsoft says RC4 constitutes less than 0.1% of its traffic, cites compatibility concerns, and plans to disable RC4 by default in certain Active Directory deployments starting Q1 2026 with additional mitigations.