Detection: Windows Unsecured Outlook Credentials Access In Registry

Updated Date: 2024-11-28 ID: 36334123-077d-47a2-b70c-6c7b3cc85049 Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

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.

Search

1`wineventlog_security` EventCode=4663 object_file_path IN ("*\\Profiles\\Outlook\\9375CFF0413111d3B88A00104B2A6676*", "*\\Windows Messaging Subsystem\\Profiles\\9375CFF0413111d3B88A00104B2A6676*") AND process_name != *\\outlook.exe 
2| 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 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_unsecured_outlook_credentials_access_in_registry_filter`

Data Source

Name	Platform	Sourcetype	Source
Windows Event Log Security 4663	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_unsecured_outlook_credentials_access_in_registry_filter	`search *`

windows_unsecured_outlook_credentials_access_in_registry_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
T1552	Unsecured Credentials	Credential Access

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

Volt Typhoon

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 Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

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.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A suspicious process $process_name$ accessing outlook credentials registry on $dest$	49	70	70

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Security`	`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: 4