FortiSIEM Rules

Website access policy violation

Rule ID

PH_Rule_PolicyViolation_4

Default Status

Enabled

Description

Network IPS or Security Gateway or Firewall detects inappropriate website access

Severity

5

Category

Security

MITRE ATT&CK® Tactics

Policy Violation

MITRE ATT&CK® Techniques

No Technique Specified

Impacts

Application

Data Source

FortiGate via Syslog, FortiProxy via Syslog, FortiWeb via Syslog, TrendMicro Interscan Web Security via Syslog, Sophos Web Filter via Syslog

Detection

Correlation

Remediation Guidance

No remediation guidance specified

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

600 seconds

Trigger Conditions

If the following defined pattern/s occur within a 600 second time window.

WebViolation OR FortiGate

Global Constraint

This defines how two or more distinct events are related in a time-series based action. e.g. An event occurs followed by another event if the source IP, user, and messageId are the same

WebViolation.srcIpAddr = FortiGate.srcIpAddr AND WebViolation.webCategory = FortiGate.webCategory

SubPattern Definitions

SubPattern Name: WebViolation

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType IN (Group@PH_SYS_EVENT_WebsiteCategoryViolation)

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID

srcIpAddr,webCategory

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1
Operator Rank: 0 Operator Type: OR

This operator defines the logic condition relating to the prior event subpattern clause and the following event subpattern clause

SubPattern Name: FortiGate

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType IN ("FortiGate-webfilter-url-firewall-deny","FortiGate-webfilter-url-firewall-allow")  AND  webCategory IN ("Malicious Websites")

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID

srcIpAddr,webCategory

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1

Incident Attribute Mapping

This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.

The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern

 srcIpAddr = WebViolation.srcIpAddr,
 webCategory = WebViolation.webCategory,
 srcIpAddr = FortiGate.srcIpAddr,
 webCategory = FortiGate.webCategory