Detection rules › Sigma

Windows Network Access Suspicious desktop.ini Action

Severity
medium
Author
Tim Shelton (HAWK.IO)
Source
upstream

Detects unusual processes accessing desktop.ini remotely over network share, which can be leveraged to alter how Explorer displays a folder's content (i.e. renaming files) without changing them on disk.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1547.009 Boot or Logon Autostart Execution: Shortcut Modification
Privilege EscalationT1547.009 Boot or Logon Autostart Execution: Shortcut Modification

Event coverage

ProviderEvent IDTitle
Security-Auditing5145A network share object was checked to see whether client can be granted desired access.

Stages and Predicates

Stage 1: selection

or:
AccessList|contains: AddSubdirectory
AccessList|contains: AppendData
AccessList|contains: DELETE
AccessList|contains: WriteDAC
AccessList|contains: WriteData
ObjectType: File
RelativeTargetName|endswith: '\desktop.ini'

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
AccessListmatch
  • AddSubdirectory
  • AppendData
  • DELETE
  • WriteDAC
  • WriteData corpus 4 (sigma 4)
ObjectTypeeq
  • File corpus 5 (sigma 3, splunk 2)
RelativeTargetNameends_with
  • \desktop.ini

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.