Security News Internet Storm Center Tip of the Day US-Cert Alerts threatpost Reddit r/netsec NVD Analyzed Pro-Russia Hacktivists Conduct Opportunistic Attacks Against US and Global Critical Infrastructure Source: US-Cert Alerts Published on 2025-12-05 CISA Shares Lessons Learned from an Incident Response Engagement Source: US-Cert Alerts Published on 2025-09-22