Suspicious GRUB Bootloader Script Modification for Bootkit Persistence
- Product
- linux
- Category
- process_creation
- Author
- HuntRule
- Published
- 2026-09-18
- Updated
- 2026-09-18
ATT&CK techniques
Persistence → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects shell modification of GRUB bootloader scripts under /etc/grub.d, a pre-OS persistence technique from the Elastic Linux persistence grand finale. Injecting commands into GRUB configuration lets an attacker gain execution before the operating system loads for stealthy and resilient persistence. Direct edits to these scripts outside of kernel or bootloader updates should be examined.
Reporting behind it
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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