RunDLL Loading DLL By Ordinal

Original Source: [splunk source]
Name:RunDLL Loading DLL By Ordinal
id:6c135f8d-5e60-454e-80b7-c56eed739833
version:8
date:2024-09-30
author:Michael Haag, David Dorsey, Splunk
status:production
type:TTP
Description:The following analytic detects rundll32.exe loading a DLL export function by ordinal value. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process command-line executions. This behavior is significant because adversaries may use rundll32.exe to execute malicious code while evading security tools that do not monitor this process. If confirmed malicious, this activity could allow attackers to execute arbitrary code, potentially leading to system compromise, privilege escalation, or persistent access within the environment.
Data_source:
  • -Sysmon EventID 1
  • -Windows Event Log Security 4688
  • -CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_rundll32` by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| where match(process,"rundll32.+\#\d+")
| `rundll_loading_dll_by_ordinal_filter`


how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives:False positives are possible with native utilities and third party applications. Filtering may be needed based on command-line, or add world writeable paths to restrict query.
References:
  -https://thedfirreport.com/2022/02/07/qbot-likes-to-move-it-move-it/
  -https://twitter.com/M_haggis/status/1491109262428635136
  -https://twitter.com/pr0xylife/status/1590394227758104576
drilldown_searches:
name:'View the detection results for - "$dest$" and "$user$"'
search:'%original_detection_search% | search dest = "$dest$" user = "$user$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$dest$" and "$user$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'Unusual Processes'
    - 'Suspicious Rundll32 Activity'
    - 'Living Off The Land'
    - 'IcedID'
  asset_type:Endpoint
  confidence:70
  impact:70
  message:A rundll32 process $process_name$ with ordinal parameter like this process commandline $process$ on host $dest$.
  mitre_attack_id:
    - 'T1218'
    - 'T1218.011'
  observable:
    name:'dest'
    type:'Hostname'
    - role:
      - 'Victim'
    name:'user'
    type:'User'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Processes.dest'
    - 'Processes.user'
    - 'Processes.parent_process_name'
    - 'Processes.parent_process'
    - 'Processes.original_file_name'
    - 'Processes.process_name'
    - 'Processes.process'
    - 'Processes.process_id'
    - 'Processes.parent_process_path'
    - 'Processes.process_path'
    - 'Processes.parent_process_id'
  risk_score:49
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.011/atomic_red_team/ordinal_windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None