H-ISAC TLP Green: Daily Cyber Headlines - December 3, 2025

Today’s Headlines:  

Leading Story

• Microsoft Defender Portal Outage Disrupts Security Alert Visibility

Data Breaches & Data Leaks

• Brsk Investigates Security Incident Involving Stolen Customer Records

Cyber Crimes & Incidents

• Fake Calendly Invites Spoof Top Brands to Hijack Ad Manager Accounts
• Cybercrime Becomes a Service Economy: Tools, Access, and Infrastructure for Rent
• North Korea’s IT Worker Fraud: Engineers Enticed to Rent Identities for State-Sponsored Remote Jobs

Vulnerabilities & Exploits  

• Apache Struts Vulnerability Lets Attackers Trigger Disk Exhaustion Attacks

Trends & Reports

• Trend Micro Warns of Autonomous AI Ransomware Threats by 2026

Privacy, Legal & Regulatory

• Australia Rolls Out AI Roadmap, Steps Back From Tougher Rules

Upcoming Health-ISAC Events

• Global Monthly Threat Brief   
  • Americas – December 16, 2025, 12:00-01:00 PM ET
  • European – December 17, 2025, 03:00-04:00 PM CET
  • Fall Americas Summit – Carlsbad, California – December 1-5, 2025

View the detailed report below.