Detection rules › Splunk
Windows Known Abused DLL Loaded Suspiciously
The following analytic detects when DLLs with known abuse history are loaded from an unusual location. This activity may represent an attacker performing a DLL search order or sideload hijacking technique. These techniques are used to gain persistence as well as elevate privileges on the target system. This detection relies on Sysmon EID7 and is compatible with all Officla Sysmon TA versions.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1574.001 Hijack Execution Flow: DLL |
| Stealth | T1574.001 Hijack Execution Flow: DLL |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 7 | Image loaded |
Rule body splunk
name: Windows Known Abused DLL Loaded Suspiciously
id: dd6d1f16-adc0-4e87-9c34-06189516b803
version: 12
creation_date: '2024-04-06'
modification_date: '2026-05-13'
author: Steven Dick
status: production
type: TTP
description: The following analytic detects when DLLs with known abuse history are loaded from an unusual location. This activity may represent an attacker performing a DLL search order or sideload hijacking technique. These techniques are used to gain persistence as well as elevate privileges on the target system. This detection relies on Sysmon EID7 and is compatible with all Officla Sysmon TA versions.
data_source:
- Sysmon EventID 7
search: '`sysmon` ImageLoaded EventCode=7 NOT ImageLoaded IN ("*\\Program Files*","*\\system32\\*", "*\\syswow64\\*","*\\winsxs\\*","*\\wbem\\*") | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest process_exec process_guid process_hash process_id process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product loaded_file | rename Image as process | eval process_name = case(isnotnull(process),replace(process,"(.*\\\)(?=.*(\.\w*)$|(\w+)$)","")), loaded_file_path = case(isnotnull(loaded_file), replace(loaded_file, "(:[\w\. ]+)", "")), loaded_file = case(isnotnull(loaded_file),replace(loaded_file,"(.*\\\)(?=.*(\.\w*)$|(\w+)$)","")), user = case(NOT user IN ("-"), replace(user, "(.*)\\\(.+)$","\2")) | lookup hijacklibs_loaded library AS loaded_file OUTPUT islibrary comment as desc | lookup hijacklibs_loaded library AS loaded_file excludes as loaded_file_path OUTPUT islibrary as excluded | search islibrary = TRUE AND excluded = false | stats count min(_time) as firstTime max(_time) as lastTime by dest loaded_file loaded_file_path process process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_known_abused_dll_loaded_suspiciously_filter`'
how_to_implement: The following analytic requires Sysmon operational logs to be imported, with EID7 being mapped to the process_name field. Modify the sysmon macro as needed to match the sourcetype or add index.
known_false_positives: DLLs being loaded by user mode programs for legitimate reasons.
references:
- https://attack.mitre.org/techniques/T1574/002/
- https://hijacklibs.net/api/
- https://wietze.github.io/blog/hijacking-dlls-in-windows
- https://github.com/olafhartong/sysmon-modular/pull/195/files
drilldown_searches:
- name: View the detection results for - "$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 ("$dest$", "$user$") | 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: 7d
latest_offset: "0"
finding:
title: The module [$loaded_file$] was loaded from an unusual location.
entity:
field: dest
type: system
score: 50
analytic_story:
- SolarWinds WHD RCE Post Exploitation
- Windows Defense Evasion Tactics
- Living Off The Land
asset_type: Endpoint
mitre_attack_id:
- T1574.001
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/T1574.002/hijacklibs/hijacklibs_sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: search
`sysmon` ImageLoaded EventCode=7 NOT ImageLoaded IN ("*\\Program Files*","*\\system32\\*", "*\\syswow64\\*","*\\winsxs\\*","*\\wbem\\*")
Stage 2: stats
| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest process_exec process_guid process_hash process_id process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product loaded_file
Stage 3: rename
| rename Image as process
Stage 4: eval
| eval process_name = case(isnotnull(process),replace(process,"(.*\\\)(?=.*(\.\w*)$|(\w+)$)","")), loaded_file_path = case(isnotnull(loaded_file), replace(loaded_file, "(:[\w\. ]+)", "")), loaded_file = case(isnotnull(loaded_file),replace(loaded_file,"(.*\\\)(?=.*(\.\w*)$|(\w+)$)","")), user = case(NOT user IN ("-"), replace(user, "(.*)\\\(.+)$","\2"))
loaded_file =replace(loaded_file, "(.*\\\)(?=.*(\.\w*)$|(\w+)$)", "")loaded_file_path =replace(loaded_file, "(:[\w\. ]+)", "")process_name =replace(process, "(.*\\\)(?=.*(\.\w*)$|(\w+)$)", "")user =replace(user, "(.*)\\\(.+)$", "\2")Stage 5: lookup
| lookup hijacklibs_loaded library AS loaded_file OUTPUT islibrary comment as desc
Stage 6: lookup
| lookup hijacklibs_loaded library AS loaded_file excludes as loaded_file_path OUTPUT islibrary as excluded
Stage 7: search
| search islibrary = TRUE AND excluded = false
Stage 8: stats
| stats count min(_time) as firstTime max(_time) as lastTime by dest loaded_file loaded_file_path process 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 9: search
| `security_content_ctime(firstTime)`
Stage 10: search
| `security_content_ctime(lastTime)`
Stage 11: search
| `windows_known_abused_dll_loaded_suspiciously_filter`
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
ImageLoaded | in | "*\\Program Files*", "*\\system32\\*", "*\\syswow64\\*", "*\\wbem\\*", "*\\winsxs\\*" |
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.
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.
| Stage | Term |
|---|---|
| 1 | ImageLoaded |