FortiSIEM Rules

Windows: Audit CVE Event

Rule ID

PH_Rule_SIGMA_1788

Default Status

Enabled

Description

Detects events generated by user-mode applications when they call the CveEventWrite API when a known vulnerability is trying to be exploited. MS started using this log in Jan. 2020 with CVE-2020-0601 (a Windows CryptoAPI vulnerability. Unfortunately, that is about the only instance of CVEs being written to this log. . This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/application/microsoft-windows_audit_cve/win_audit_cve.yml

Severity

9

Category

Security

MITRE ATT&CK® Tactics

Impact

Impact consists of techniques that adversaries use to disrupt availability or compromise integrity by manipulating business and operational processes. Techniques used for impact can include destroying or tampering with data. In some cases, business processes can look fine, but may have been altered to benefit the adversaries’ goals. These techniques might be used by adversaries to follow through on their end goal or to provide cover for a confidentiality breach.

https://attack.mitre.org/tactics/TA0040

MITRE ATT&CK® Techniques


T1499.004

Endpoint Denial of Service: Application or System Exploitation

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users. (Citation: Sucuri BIND9 August 2015) Some systems may automatically restart critical applications and services when crashes occur, but they can likely be re-exploited to cause a persistent DoS condition.

https://attack.mitre.org/techniques/T1499/004

Impacts

Server

Data Source

Windows Application Log Via OMI or FortiSIEM Agent

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.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.

Filter

SubPattern Definitions

SubPattern Name: Filter

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="Win-App-Microsoft-Windows-Audit-CVE-1"

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

hostName

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

hostName = Filter.hostName