Detection rules › Splunk

Windows Input Capture Using Credential UI Dll

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects a process loading the credui.dll or wincredui.dll module. This detection leverages Sysmon EventCode 7 to identify instances where these DLLs are loaded by processes outside typical system directories. This activity is significant because adversaries often abuse these modules to create fake credential prompts or dump credentials, posing a risk of credential theft. If confirmed malicious, this activity could allow attackers to harvest user credentials, leading to unauthorized access and potential lateral movement within the network.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1056.002 Input Capture: GUI Input Capture
CollectionT1056.002 Input Capture: GUI Input Capture

Event coverage

ProviderEvent IDTitle
Sysmon7Image loaded

Stages and Predicates

Stage 1: search

search ((NOT Image IN ("*:\\program files*", "*\\windows\\explorer.exe", "*\\windows\\sysWow64\\*", "*\\windows\\system32\\*") ImageLoaded="*\\wincredui.dll" OriginalFileName="wincredui.dll") OR (ImageLoaded="*\\credui.dll" OriginalFileName="credui.dll")) EventCode=7

Stage 2: fillnull

fillnull

Stage 3: stats

stats 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

search

Stage 5: search

search

Stage 6: search

search `macro`

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.

FieldKindValues
EventCodeeq
  • 7 corpus 35 (splunk 35)
ImageLoadedeq
  • "*\\credui.dll"
  • "*\\wincredui.dll"
OriginalFileNameeq
  • "credui.dll"
  • "wincredui.dll"

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.