Windows: NTFS Vulnerability Exploitation

Rule ID

PH_Rule_SIGMA_1139

Default Status

Enabled

Description

This the exploitation of a NTFS vulnerability as reported without many details via Twitter. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/system/ntfs/win_system_ntfs_vuln_exploit.yml

Severity

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

T1499.001

Endpoint Denial of Service: OS Exhaustion Flood

Adversaries may target the operating system (OS) for a DoS attack, since the (OS) is responsible for managing the finite resources on a system. These attacks do not need to exhaust the actual resources on a system since they can simply exhaust the limits that an OS self-imposes to prevent the entire system from being overwhelmed by excessive demands on its capacity.

https://attack.mitre.org/techniques/T1499/001

Impacts

Server

Data Source

Windows System 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-System-Ntfs-55" AND origLocation="File System Driver" AND description REGEXP ".*contains a corrupted file record.*" AND description REGEXP ".*The name of the file is \"\\\".*"

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

description,hostName,origLocation

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

description = Filter.description,
hostName = Filter.hostName,
origLocation = Filter.origLocation

FortiSIEM Rules