Detection: No Windows Updates in a time frame

EXPERIMENTAL DETECTION

This detection status is set to experimental. The Splunk Threat Research team has not yet fully tested, simulated, or built comprehensive datasets for this detection. As such, this analytic is not officially supported. If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2024-05-15 ID: 1a77c08c-2f56-409c-a2d3-7d64617edd4f Author: Bhavin Patel, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies Windows endpoints that have not generated an event indicating a successful Windows update in the last 60 days. It leverages the 'Update' data model in Splunk, specifically looking for the latest 'Installed' status events from Microsoft Windows. This activity is significant for a SOC because endpoints that are not regularly patched are vulnerable to known exploits and security vulnerabilities. If confirmed malicious, this could indicate a compromised endpoint that is intentionally being kept unpatched, potentially allowing attackers to exploit unpatched vulnerabilities and gain unauthorized access or control.

Search

 1
 2| tstats `security_content_summariesonly` max(_time) as lastTime from datamodel=Updates where Updates.status=Installed Updates.vendor_product="Microsoft Windows" by Updates.dest Updates.status Updates.vendor_product 
 3| rename Updates.dest as Host 
 4| rename Updates.status as "Update Status" 
 5| rename Updates.vendor_product as Product 
 6| eval isOutlier=if(lastTime <= relative_time(now(), "-60d@d"), 1, 0)  
 7| `security_content_ctime(lastTime)`  
 8| search isOutlier=1 
 9| rename lastTime as "Last Update Time", 
10| table Host, "Update Status", Product, "Last Update Time" 
11| `no_windows_updates_in_a_time_frame_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
N/A	N/A	N/A	N/A	N/A

Macros Used

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

no_windows_updates_in_a_time_frame_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

NistCategory.DE_AE

Cis18Value.CIS_10

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	False

This configuration file applies to all detections of type hunting.

Implementation

To successfully implement this search, it requires that the 'Update' data model is being populated. This can be accomplished by ingesting Windows events or the Windows Update log via a universal forwarder on the Windows endpoints you wish to monitor. The Windows add-on should be also be installed and configured to properly parse Windows events in Splunk. There may be other data sources which can populate this data model, including vulnerability management systems.

Known False Positives

None identified

Associated Analytic Story

Monitor for Updates

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
tbd	25	50	50

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

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	Not Applicable	N/A	N/A	N/A
Unit	❌ Failing	N/A	`N/A`	`N/A`
Integration	❌ Failing	N/A	`N/A`	`N/A`

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: 2