BlackX UEFI Bootkit Bypasses Secure Boot via Missing DBX Revocations

Sat, 24 Oct 2026 14:29:02 +0000

Engineer — Plan: The bypass exploits outdated UEFI Secure Boot revocation databases (DBX) rather than an unpatched flaw — audit all Windows endpoints and servers to confirm DBX revocation lists are current, and verify that UEFI firmware update policies include revocation database refresh.
SOC/IR — Plan: APT41’s deployment of a new UEFI-level bootkit warrants reviewing Kaspersky’s technical report for IOCs and ATT&CK mappings, then building or tuning detections for Secure Boot bypass behaviors (e.g., unexpected bootloader measurements, DBX modification events) in EDR and firmware telemetry.
Leader — Learn: A China-nexus group’s use of firmware-level persistence against diplomatic targets is a useful data point for risk posture discussions, but the campaign’s narrow targeting of Central Asian diplomatic entities means no immediate board-level action is required for most organizations.

Apt41 on CuraSec