Detection rules › Splunk

SchCache Change By App Connect And Create ADSI Object

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects an application attempting to connect and create an ADSI object to perform an LDAP query. It leverages Sysmon EventCode 11 to identify changes in the Active Directory Schema cache files located in %LOCALAPPDATA%\Microsoft\Windows\SchCache or %systemroot%\SchCache. This activity is significant as it can indicate the presence of suspicious applications, such as ransomware, using ADSI object APIs for LDAP queries. If confirmed malicious, this behavior could allow attackers to gather sensitive directory information, potentially leading to further exploitation or lateral movement within the network.

MITRE ATT&CK coverage

TacticTechniques
DiscoveryT1087.002 Account Discovery: Domain Account

Event coverage

ProviderEvent IDTitle
Sysmon11FileCreate

Stages and Predicates

Stage 1: search

search NOT Image="*\\Windows\\system32\\mmc.exe" EventCode=11 TargetFilename="*.sch*" TargetFilename="*\\Windows\\SchCache\\*"

Stage 2: stats

stats BY action, dest, file_name, file_path, process_guid, process_id, user_id, vendor_product, process_name

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
1Imageeq"*\\Windows\\system32\\mmc.exe"

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
EventCodeeq
  • 11 corpus 10 (splunk 10)
TargetFilenameeq
  • "*.sch*"
  • "*\\Windows\\SchCache\\*"