Detection rules › Elastic

Potential Credential Access via Renamed COM+ Services DLL

Author
Elastic
Source
upstream

Identifies suspicious renamed COMSVCS.DLL Image Load, which exports the MiniDump function that can be used to dump a process memory. This may indicate an attempt to dump LSASS memory while bypassing command-line based detection in preparation for credential access.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1036 Masquerading, T1036.003 Masquerading: Rename Legitimate Utilities, T1218 System Binary Proxy Execution, T1218.011 System Binary Proxy Execution: Rundll32
Credential AccessT1003 OS Credential Dumping, T1003.001 OS Credential Dumping: LSASS Memory

Event coverage

ProviderEvent IDTitle
Sysmon7Image loaded

Stages and Predicates

Stage 1: eql:process

event.category:"process" and process.name:"rundll32.exe"

Stage 2: eql:process

not file.name:"COMSVCS.DLL" and (file.pe.imphash:"EADBCCBB324829ACB5F2BBE87E5549A8" or file.pe.original_file_name:"COMSVCS.DLL") and data_stream.dataset:"windows.sysmon_operational" and event.category:"process"

Exclusions

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

StageFieldKindExcluded values
1file.nameeqCOMSVCS.DLL

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
data_stream.datasetwildcard
  • windows.sysmon_operational
event.categoryeq
  • process corpus 2 (elastic 2)
file.pe.imphashwildcard
  • EADBCCBB324829ACB5F2BBE87E5549A8
file.pe.original_file_namewildcard
  • COMSVCS.DLL
process.namewildcard
  • rundll32.exe