Patch, track, repeat: The 2025 CVE retrospective

Welcome to this week's edition of the Threat Source newsletter. It's time to look back at a year that pushed the vulnerability landscape to new heights. I'll admit this retrospective is arriving a bit later than planned. With 48,196 CVEs in 2025 a stunning 132 vulnerabilities per day, the analysi...

Enhanced Monitoring to Detect APT Activity Targeting Outlook Online

SUMMARY In June 2023, a Federal Civilian Executive Branch FCEB agency identified suspicious activity in their Microsoft 365 M365 cloud environment. The agency reported the activity to Microsoft and the Cybersecurity and Infrastructure Security Agency CISA, and Microsoft determined that advanced...

CISA and FBI Release Cybersecurity Advisory on Enhanced Monitoring to Detect APT Activity Targeting Outlook Online

The Cybersecurity and Infrastructure Security Agency CISA and Federal Bureau of Investigation FBI have released a joint Cybersecurity Advisory CSA, Enhanced Monitoring to Detect APT Activity Targeting Outlook Online, to provide guidance to agencies and critical infrastructure organizations on...