Try in Splunk Security Cloud

Description

The following analytic identifies modifications to specific Outlook registry values related to WebView and Today features. It detects when a URL is set in these registry locations, which could indicate attempts to manipulate Outlook's web-based components. The analytic focuses on changes to the "URL" value within Outlook's WebView and Today registry paths. This activity is significant as it may represent an attacker's effort to redirect Outlook's web content or inject malicious URLs. If successful, this technique could lead to phishing attempts, data theft, or serve as a stepping stone for further compromise of the user's email client and potentially sensitive information.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint, Web
  • Last Updated: 2024-07-30
  • Author: Michael Haag, Splunk
  • ID: 6e1ad5d4-d9af-496a-96ec-f31c11cd09f2

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1112 Modify Registry Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6



| tstats `security_content_summariesonly` count values(Registry.registry_value_name) as registry_value_name values(Registry.registry_value_data) as registry_value_data min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where (Registry.registry_path="*\\Software\\Microsoft\\Office\\*\\Outlook\\WebView\\*" OR Registry.registry_path="*\\Software\\Microsoft\\Office\\*\\Outlook\\Today") AND Registry.registry_value_name="URL" by Registry.dest, Registry.user, Registry.registry_path 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `drop_dm_object_name(Registry)` 
| `windows_outlook_webview_registry_modification_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_outlook_webview_registry_modification_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • Registry.dest
  • Registry.user
  • Registry.registry_path
  • Registry.registry_value_name
  • Registry.registry_value_data

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

False positives may occur if legitimate Outlook processes are modified.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
100.0 100 100 Modification of Outlook WebView registry values on $dest$.

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

Reference

Test Dataset

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 | version: 1