Detection: Registry Keys Used For Persistence

Updated Date: 2024-09-30 ID: f5f6af30-7aa7-4295-bfe9-07fe87c01a4b Author: Jose Hernandez, David Dorsey, Teoderick Contreras, Rod Soto, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies modifications to registry keys commonly used for persistence mechanisms. It leverages data from endpoint detection sources like Sysmon or Carbon Black, focusing on specific registry paths known to initiate applications or services during system startup. This activity is significant as unauthorized changes to these keys can indicate attempts to maintain persistence or execute malicious actions upon system boot. If confirmed malicious, this could allow attackers to achieve persistent access, execute arbitrary code, or maintain control over compromised systems, posing a severe threat to system integrity and security.

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where (Registry.registry_path=*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\RunOnce OR Registry.registry_path=*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\StartupApproved\\Run OR Registry.registry_path= "*\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders\\*" OR Registry.registry_path= "*\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders\\*" OR Registry.registry_path=*\\currentversion\\run* OR Registry.registry_path=*\\currentVersion\\Windows\\Appinit_Dlls* OR Registry.registry_path=*\\CurrentVersion\\Winlogon\\Shell* OR Registry.registry_path=*\\CurrentVersion\\Winlogon\\Notify* OR Registry.registry_path=*\\CurrentVersion\\Winlogon\\Userinit* OR Registry.registry_path=*\\CurrentVersion\\Winlogon\\VmApplet* OR Registry.registry_path=*\\currentversion\\policies\\explorer\\run* OR Registry.registry_path=*\\currentversion\\runservices* OR Registry.registry_path=HKLM\\SOFTWARE\\Microsoft\\Netsh\\* OR Registry.registry_path= "*\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders\\Common Startup" OR Registry.registry_path= *\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\SharedTaskScheduler OR Registry.registry_path= *\\Classes\\htmlfile\\shell\\open\\command OR (Registry.registry_path="*Microsoft\\Windows NT\\CurrentVersion\\Image File Execution Options*" AND Registry.registry_key_name=Debugger) OR (Registry.registry_path="*\\CurrentControlSet\\Control\\Lsa" AND Registry.registry_key_name="Security Packages") OR (Registry.registry_path="*\\CurrentControlSet\\Control\\Lsa\\OSConfig" AND Registry.registry_key_name="Security Packages") OR (Registry.registry_path="*\\Microsoft\\Windows NT\\CurrentVersion\\SilentProcessExit\\*") OR (Registry.registry_path="*currentVersion\\Windows" AND Registry.registry_key_name="Load") OR (Registry.registry_path="*\\CurrentVersion" AND Registry.registry_key_name="Svchost") OR (Registry.registry_path="*\\CurrentControlSet\Control\Session Manager"AND Registry.registry_key_name="BootExecute") OR (Registry.registry_path="*\\Software\\Run" AND Registry.registry_key_name="auto_update")) by Registry.dest Registry.user Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.registry_key_name 
3| `drop_dm_object_name(Registry)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `registry_keys_used_for_persistence_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 12 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 13 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
registry_keys_used_for_persistence_filter search *
registry_keys_used_for_persistence_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1547.001 Registry Run Keys / Startup Folder Persistence
T1547 Boot or Logon Autostart Execution Privilege Escalation
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
APT18
APT19
APT28
APT29
APT3
APT32
APT33
APT37
APT39
APT41
BRONZE BUTLER
Cobalt Group
Confucius
Dark Caracal
Darkhotel
Dragonfly
FIN10
FIN13
FIN6
FIN7
Gamaredon Group
Gorgon Group
Higaisa
Inception
Ke3chang
Kimsuky
Lazarus Group
LazyScripter
Leviathan
LuminousMoth
Magic Hound
Molerats
Moonstone Sleet
MuddyWater
Mustang Panda
Naikon
PROMETHIUM
Patchwork
Putter Panda
RTM
RedCurl
Rocke
Sidewinder
Silence
TA2541
TeamTNT
Threat Group-3390
Tropic Trooper
Turla
Windshift
Wizard Spider
ZIRCONIUM

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.

Known False Positives

There are many legitimate applications that must execute on system startup and will use these registry keys to accomplish that task.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A registry activity in $registry_path$ related to persistence in host $dest$ 76 80 95
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 11