March 2025 monthly summary for sublime-security/sublime-rules focusing on feature enhancements and detection accuracy improvements.

February 2025: Delivered targeted security policy updates and rule tuning with clear business impact. Implemented Email Security Policy Enhancement by adding sastrify.com to high-trust sender root domains, improving deliverability and reducing spoofing risk. Refined Suspicious Request Detection Rule to reduce false positives, enhancing alert quality and security operations efficiency. Changes are fully traceable via commit references across two repositories.

December 2024: Strengthened detection rules in sublime-rules to improve phishing and scam content protection. Delivered an enhanced Cyrillic link substitution rule that triggers when attachments exist but thread text is empty, catching unsolicited substitutions that previously could slip through. The change was implemented via Update link_cyrillic_substitutions_unsolicited.yml (#2240) in the sublime-security/sublime-rules repository. Focused on risk reduction and maintainability with YAML-driven configuration updates.