Detection rules › Splunk

Windows Raw Access To Disk Volume Partition

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects suspicious raw access reads to the device disk partition of a host machine. It leverages Sysmon EventCode 9 logs to identify processes attempting to read or write to the boot sector, excluding legitimate system processes. This activity is significant as it is commonly associated with destructive actions by adversaries, such as wiping, encrypting, or overwriting the boot sector, as seen in attacks involving malware like HermeticWiper. If confirmed malicious, this behavior could lead to severe impacts, including system inoperability, data loss, or compromised boot integrity.

MITRE ATT&CK coverage

TacticTechniques
ImpactT1561.002 Disk Wipe: Disk Structure Wipe

Event coverage

ProviderEvent IDTitle
Sysmon9RawAccessRead

Stages and Predicates

Stage 1: search

search NOT Image IN ("*\\Windows\\SysWOW64\\*", "*\\Windows\\System32\\*") Device="\\\\Device\\\\HarddiskVolume*" EventCode=9

Stage 2: stats

stats BY dest, dvc, process_exec, process_guid, process_id, process_name, process_path, signature, signature_id, user_id, vendor_product, Device, Image

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

Exclusions

Top-level NOT(...) conjuncts — predicates this rule actively suppresses.

StageFieldKindExcluded values
1Imagein"*\\Windows\\SysWOW64\\*", "*\\Windows\\System32\\*"

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Deviceeq
  • \\Device\\HarddiskVolume*
EventCodeeq
  • 9 corpus 2 (splunk 2)