FortiSIEM Rules

Server Network Interface Flapping

Rule ID

PH_Rule_Avail_13

Default Status

Enabled

Description

Detects that a network interface of a server is flapping - that is, coming up and down more than 3 times in 15 minutes. This may indicate hardware issues.

Severity

7

Category

Availability

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


T1529

System Shutdown/Reboot

Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems.

https://attack.mitre.org/techniques/T1529

Impacts

Server

Data Source

Any Device via SNMP

Detection

Correlation

Remediation Guidance

Identify the root cause and solve the issue

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.

IntfDownSrv AND IntfUpSrv

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

IntfDownSrv.hostIpAddr = IntfUpSrv.hostIpAddr AND IntfDownSrv.intfName = IntfUpSrv.intfName

SubPattern Definitions

SubPattern Name: IntfDownSrv

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_NetIntfShutdown) 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, intfName

Aggregate Constraint

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

COUNT(*) >= 3
Operator Rank: 0 Operator Type: AND

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

SubPattern Name: IntfUpSrv

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_NetIntfRestart) 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,intfName

Aggregate Constraint

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

COUNT(*) >= 3

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 = IntfDownSrv.hostIpAddr,
 hostName = IntfDownSrv.hostName,
 intfName = IntfDownSrv.intfName