Detection rules › Splunk

Add DLL_EXE Registry Value (Sysmon)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in

MITRE ATT&CK coverage

References

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body yaml

id: '1093.1147'
title: Add DLL_EXE Registry Value
description: 'Adding an entry to the "run keys" in the Registry or startup folder
  will cause the program referenced to be executed when a user logs in. -- Threat
  Actor Association: CL-STA-0043, FamousSparrow, FIN6, Flax Typhoon, WIRTE -- Software
  Association: Blackbyte'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` ( signature_id=13 AND (TERM(HKU)
  OR TERM(HKCU) OR TERM(HKLM)) AND (registry_value_name="*\\Temp\\*.exe" OR registry_value_name="*\\Temp\\*.dll"
  OR registry_value_name="*\\Common Files\\*.dll" OR registry_value_name="*\\Common
  Files\\*.exe") ) | table _time, host, user, process process_name, parent_process_name,
  signature_id, dest_ip, registry_value_name | bin span=1s | stats values(*) as *
  by _time, host | table _time, host, user, process process_name, parent_process_name,
  signature_id dest_ip registry_value_name `hec_collect`'
techniques:
- persistence:boot or logon autostart execution:registry run keys / startup folder
technique_id:
- T1547.001
data_category:
- Windows Registry
- Windows Sysmon
references:
- https://www.hackingarticles.in/multiple-ways-to-persistence-on-windows-10-with-metasploit/
- https://blog.talosintelligence.com/2021/09/tinyturla.html

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_sysmon` ( signature_id=13 AND (TERM(HKU) OR TERM(HKCU) OR TERM(HKLM)) AND (registry_value_name="*\\Temp\\*.exe" OR registry_value_name="*\\Temp\\*.dll" OR registry_value_name="*\\Common Files\\*.dll" OR registry_value_name="*\\Common Files\\*.exe") )

Stage 2: table

| table _time, host, user, process process_name, parent_process_name, signature_id, dest_ip, registry_value_name

Stage 3: bucket

| bin span=1s

Stage 4: stats

| stats values(*) as * by _time, host

Stage 5: table

| table _time, host, user, process process_name, parent_process_name, signature_id dest_ip registry_value_name `hec_collect`

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
registry_value_nameeq
  • "*\\Common Files\\*.dll"
  • "*\\Common Files\\*.exe"
  • "*\\Temp\\*.dll"
  • "*\\Temp\\*.exe"
signature_ideq
  • 13

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
1TERM
1HKU
1TERM
1HKCU
1TERM
1HKLM