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Hi3519 U-Boot Hard-Coded AES Kernel Key: Detection & IOCs

The Hi3519 bootloader embeds its kernel AES key, so kernels decrypt offline from vendor firmware. 9 detection rules, 11 IOCs and a free Splunk SPL rule.

Read the full threat intel for Hi3519 U-Boot Hard-Coded AES Kernel Key: Detection & IOCs →

Chapters

  1. 0:00The hookHard-coded bootloader key recovered in lab emulation.
  2. 0:04The storyResearchers published analysis of Hi3519 bootloader encryption.
  3. 0:13Attack pathBinwalk unpacked the firmware, entropy analysis showed encryption.
  4. 0:31AttributionNo threat actor: this was defensive research.
  5. 0:35Indicators of compromise3 indicators to hunt: 1 hash and 2 file names.
  6. 0:40MITRE ATT&CK techniques5 ATT&CK techniques, from reconnaissance to credential access.
  7. 0:44Remediation2 steps now: Treat the kernel encryption key in affected bootloaders as compromised.
  8. 0:51Detection rules9 detection rules, in SPL, KQL and Sigma.
Transcript

0:00Hard-coded bootloader key recovered in lab emulation.

0:05Researchers published analysis of Hi3519 bootloader encryption.

0:11They emulated the AES decryption.

0:14Binwalk unpacked the firmware, entropy analysis showed encryption.

0:18Ghidra mapped memory and identified AES in U-Boot.

0:22Rather than reimplement, they chose Unicorn Engine emulation.

0:26Emulation decrypted the kernel. Image magic verified success.

0:32No threat actor: this was defensive research.

0:363 indicators to hunt: 1 hash and 2 file names.

0:415 ATT&CK techniques, from reconnaissance to credential access.

0:452 steps now: Treat the kernel encryption key in affected bootloaders as compromised.

0:519 detection rules, in SPL, KQL and Sigma.

0:56Threadlinqs. The unified security engineering platform.