Detection rules › Splunk
Windows Unsecured Outlook Credentials Access In Registry
The following analytic detects unauthorized access to Outlook credentials stored in the Windows registry. It leverages Windows Security Event logs, specifically EventCode 4663, to identify access attempts to registry paths associated with Outlook profiles. This activity is significant as it may indicate attempts to steal sensitive email credentials, which could lead to unauthorized access to email accounts. If confirmed malicious, this could allow attackers to exfiltrate sensitive information, impersonate users, or execute further unauthorized actions within Outlook, posing a significant security risk.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1552 Unsecured Credentials |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4663 | An attempt was made to access an object. |
Rule body splunk
name: Windows Unsecured Outlook Credentials Access In Registry
id: 36334123-077d-47a2-b70c-6c7b3cc85049
version: 13
creation_date: '2024-02-22'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects unauthorized access to Outlook credentials stored in the Windows registry. It leverages Windows Security Event logs, specifically EventCode 4663, to identify access attempts to registry paths associated with Outlook profiles. This activity is significant as it may indicate attempts to steal sensitive email credentials, which could lead to unauthorized access to email accounts. If confirmed malicious, this could allow attackers to exfiltrate sensitive information, impersonate users, or execute further unauthorized actions within Outlook, posing a significant security risk.
data_source:
- Windows Event Log Security 4663
search: '`wineventlog_security` EventCode=4663 object_file_path IN ("*\\Profiles\\Outlook\\9375CFF0413111d3B88A00104B2A6676*", "*\\Windows Messaging Subsystem\\Profiles\\9375CFF0413111d3B88A00104B2A6676*") AND process_name != *\\outlook.exe | stats count min(_time) as firstTime max(_time) as lastTime by object_file_name object_file_path process_name process_path process_id EventCode dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_unsecured_outlook_credentials_access_in_registry_filter`'
how_to_implement: To successfully implement this search, you must ingest Windows Security Event logs and track event code 4663. For 4663, enable "Audit Object Access" in Group Policy. Then check the two boxes listed for both "Success" and "Failure."
known_false_positives: third party software may access this outlook registry.
references:
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/choice
- https://malpedia.caad.fkie.fraunhofer.de/details/win.404keylogger
drilldown_searches:
- name: View the detection results for - "$dest$"
search: '%original_detection_search% | search dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | 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"
intermediate_findings:
entities:
- field: dest
type: system
score: 20
message: A suspicious process $process_name$ accessing outlook credentials registry on $dest$
analytic_story:
- StealC Stealer
- Snake Keylogger
- Meduza Stealer
- 0bj3ctivity Stealer
- Lokibot
- VIP Keylogger
asset_type: Endpoint
mitre_attack_id:
- T1552
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/T1552/snakey_keylogger_outlook_reg_access/snakekeylogger_4663.log
source: XmlWinEventLog:Security
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: search
`wineventlog_security` EventCode=4663 object_file_path IN ("*\\Profiles\\Outlook\\9375CFF0413111d3B88A00104B2A6676*", "*\\Windows Messaging Subsystem\\Profiles\\9375CFF0413111d3B88A00104B2A6676*") AND process_name != *\\outlook.exe
Stage 2: stats
| stats count min(_time) as firstTime max(_time) as lastTime by object_file_name object_file_path process_name process_path process_id EventCode dest
Stage 3: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: search
| `windows_unsecured_outlook_credentials_access_in_registry_filter`
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 |
|
object_file_path | in |
|
process_name | ne |
|