Bootkit analysis is the specialized examination of malware that infects the boot process of a computer, loading before the operating system and its security controls. Bootkits modify the Master Boot Record (MBR), Volume Boot Record (VBR), or UEFI firmware to execute malicious code during system startup, achieving persistence that survives operating system reinstallation. Notable bootkits include TDL4, Rovnix, FinSpy bootkit, and the UEFI-targeting ESPecter and BlackLotus. Bootkit analysis requires deep understanding of the boot process, firmware interfaces, and low-level system architecture.
Analysts begin by acquiring boot sector images and firmware dumps using specialized tools. For legacy BIOS systems, the MBR (first 512 bytes of the disk) and VBR are extracted and compared against known-good templates. For UEFI systems, the EFI System Partition (ESP) is examined for unauthorized bootloaders, and firmware images are dumped for analysis. Static analysis of boot code requires understanding of 16-bit real mode and 32/64-bit protected mode assembly. Dynamic analysis uses hardware debuggers, JTAG interfaces, or specialized emulation environments that simulate the boot process. Integrity verification compares boot components against vendor-signed originals. Measured boot logs from TPM chips provide a cryptographic record of the boot chain that can reveal unauthorized modifications.
Bootkits represent the apex of persistence techniques. By loading before the operating system, they can control everything that follows, including disabling security software, hiding from detection tools, and surviving disk reformatting. UEFI bootkits like BlackLotus can even bypass Secure Boot on fully patched systems, demonstrating that firmware-level threats continue to evolve. Organizations that do not include boot integrity verification in their security posture may harbor persistent implants indefinitely, undermining all higher-level security controls.
CDA treats bootkit threats as a critical concern in the TID domain's advanced campaign tiers. Our C-DRILL missions include boot integrity verification using TPM attestation and firmware analysis tools. CDA operators learn bootkit analysis as part of the M4 Architect certification path, and our wiki maintains analysis reports on known bootkit families with detection indicators and remediation procedures.