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Description

The following analytic identifies blocked destinations within a network that are deemed privacy risks by Zscaler. It leverages web proxy logs, focusing on entries marked as "Privacy Risk." Key data points such as device owner, user, URL category, destination URL, and IP are analyzed. This activity is significant for a SOC as it helps monitor and manage privacy risks, ensuring a secure network environment. If confirmed malicious, this activity could indicate attempts to access or exfiltrate sensitive information, posing a significant threat to data privacy and security.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Risk
  • Last Updated: 2024-05-24
  • Author: Gowthamaraj Rajendran, Rod Soto, Splunk
  • ID: 5456bdef-d765-4565-8e1f-61ca027bc50d

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1566 Phishing Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`zscaler_proxy` action=blocked urlclass="Privacy Risk" 
|  stats count min(_time) as firstTime max(_time) as lastTime by action deviceowner user urlcategory url src dest 
| dedup urlcategory 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `zscaler_privacy_risk_destinations_threat_blocked_filter`

Macros

The SPL above uses the following Macros:

:information_source: zscaler_privacy_risk_destinations_threat_blocked_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.

  • action
  • threatname
  • deviceowner
  • user
  • urlcategory
  • url
  • dest
  • dest_ip
  • action

How To Implement

You must install the latest version of Zscaler Add-on from Splunkbase. You must be ingesting Zscaler events into your Splunk environment through an ingester. This analytic was written to be used with the "zscalernss-web" sourcetype leveraging the Zscaler proxy data. This enables the integration with Splunk Enterprise Security. Security teams are encouraged to adjust the detection parameters, ensuring the detection is tailored to their specific environment.

Known False Positives

False positives are limited to Zscaler configuration.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
8.0 10 80 Potential Privacy Risk Destinations from dest -[$dest$] on $src$ for user-[$user$].

: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: 2