Windows Server Paging File Usage Critical

Rule ID

PH_Rule_Perf_249

Default Status

Enabled

Description

Detects that server paging file usage has reached a critical level (greater than 98% based on 5 successive readings in a 1 hour interval. The paging file is a reserved space on disk that backes up committed physical memory on a computer

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 Performance Monitoring 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.

3600 seconds

Trigger Conditions

If the following defined pattern/s occur within a 3600 second time window.

ServPagingCrit

SubPattern Definitions

SubPattern Name: ServPagingCrit

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 = "PH_DEV_MON_SYS_PAGEFILE_USAGE" AND hostIpAddr IN (Group@PH_SYS_DEVICE_Server)

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

hostIpAddr,hostName

Aggregate Constraint

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

AVG(pageFileUsage) >= 98 AND COUNT(*) >= 5

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

 hostIpAddr = ServPagingCrit.hostIpAddr,
 hostName = ServPagingCrit.hostName,
 pageFileUsage = ServPagingCrit.AVG(pageFileUsage)

FortiSIEM Rules