GitHub Repo

Detection: Rundll32 Create Remote Thread To A Process

Updated Date: 2026-06-29 ID: 2dbeee3a-f067-11eb-96c0-acde48001122 Author: Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of a remote thread by rundll32.exe into another process. It leverages Sysmon EventCode 8 logs, specifically monitoring SourceImage and TargetImage fields. This activity is significant as it is a common technique used by malware, such as IcedID, to execute malicious code within legitimate processes, aiding in defense evasion and data theft. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, escalate privileges, and exfiltrate sensitive information from the compromised host.

 1`sysmon`
 2EventCode=8
 3SourceImage="*\\rundll32.exe"
 4TargetImage = "*.exe"
 5
 6| stats count min(_time) as firstTime
 7              max(_time) as lastTime
 8              values(NewThreadId) as "NewThreadId"
 9              values(StartAddress) as "StartAddress"
10  by dest signature_id signature
11     SourceProcessGuid SourceProcessId SourceImage
12     TargetProcessGuid TargetProcessId TargetImage
13     StartModule StartFunction vendor_product
14
15| `security_content_ctime(firstTime)`
16
17| `security_content_ctime(lastTime)`
18
19| `rundll32_create_remote_thread_to_a_process_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 8 Windows icon Windows 'XmlWinEventLog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
sysmon (source=WinEventLog:Microsoft-Windows-Sysmon/Operational OR source=XmlWinEventLog:Microsoft-Windows-Sysmon/Operational OR source=Syslog:Linux-Sysmon/Operational)
rundll32_create_remote_thread_to_a_process_filter search *
rundll32_create_remote_thread_to_a_process_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
T1055 Process Injection Privilege Escalation
Exploitation
DE.CM
CIS 10

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 Finding (Notable) Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Intermediate Finding (Risk Event) No
TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

To successfully implement this search, you need to be ingesting logs with the SourceImage, TargetImage, and EventCode executions from your endpoints related to create remote thread or injecting codes. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

No false positives have been identified at this time.

Associated Analytic Story

Finding

Title Entity Field Entity Type Risk Score
rundl32 process $SourceImage$ create a remote thread to process $TargetImage$ in host $dest$ dest system 50

Threat Objects

Field Type
SourceImage process

References

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