Detection rules › Splunk
Windows DLL Module Loaded in Temp Dir
The following analytic detects instances where a Dynamic Link Library (DLL) is loaded from a temporary directory on a Windows system. Loading DLLs from non-standard paths such as %TEMP% is uncommon for legitimate applications and is often associated with adversary tradecraft, including DLL search order hijacking, side-loading, or execution of malicious payloads staged in temporary folders. Adversaries frequently leverage these directories because they are writable by standard users and often overlooked by security controls, making them convenient locations to drop and execute malicious files. This behavior may indicate attempts to evade detection, execute unauthorized code, or maintain persistence through hijacked execution flows. Detection of DLL loads from %TEMP% can help surface early signs of compromise and should be investigated in the context of the originating process, user account, and potential file creation or modification activity within the same directory.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1105 Ingress Tool Transfer |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 7 | Image loaded |
Rule body splunk
name: Windows DLL Module Loaded in Temp Dir
id: c2998141-235a-4e31-83cf-46afb5208a87
version: 5
creation_date: '2025-08-21'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Hunting
description: The following analytic detects instances where a Dynamic Link Library (DLL) is loaded from a temporary directory on a Windows system. Loading DLLs from non-standard paths such as %TEMP% is uncommon for legitimate applications and is often associated with adversary tradecraft, including DLL search order hijacking, side-loading, or execution of malicious payloads staged in temporary folders. Adversaries frequently leverage these directories because they are writable by standard users and often overlooked by security controls, making them convenient locations to drop and execute malicious files. This behavior may indicate attempts to evade detection, execute unauthorized code, or maintain persistence through hijacked execution flows. Detection of DLL loads from %TEMP% can help surface early signs of compromise and should be investigated in the context of the originating process, user account, and potential file creation or modification activity within the same directory.
data_source:
- Sysmon EventID 7
search: '`sysmon` EventCode=7 NOT (ImageLoaded IN("C:\\Program Files*")) AND ImageLoaded="*\\temp\\*" AND ImageLoaded="*.dll" | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_dll_module_loaded_in_temp_dir_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting logs with the process name and imageloaded executions from your endpoints. 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.
references:
- https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-203a
- https://blog.sekoia.io/interlock-ransomware-evolving-under-the-radar/
analytic_story:
- SolarWinds WHD RCE Post Exploitation
- Interlock Rat
- Lokibot
asset_type: Endpoint
mitre_attack_id:
- T1105
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1105/dll_loaded_in_temp/module_loaded_in_temp.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: search
`sysmon` EventCode=7 NOT (ImageLoaded IN("C:\\Program Files*")) AND ImageLoaded="*\\temp\\*" AND ImageLoaded="*.dll"
Stage 2: fillnull
| fillnull
Stage 3: stats
| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product
Stage 4: search
| `security_content_ctime(firstTime)`
Stage 5: search
| `security_content_ctime(lastTime)`
Stage 6: search
| `windows_dll_module_loaded_in_temp_dir_filter`
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
ImageLoaded | eq | "C:\\Program Files*" |
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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
ImageLoaded | eq |
|