FortiSIEM Rules

Unusual ICMP Traffic

Rule ID

PH_Rule_Flow_204

Default Status

Enabled

Description

Detects unusual ( more than 10 in 3 minutes) ICMP types, namely other than echo request/reply and destination unreachables

Severity

7

Category

Security

MITRE ATT&CK® Tactics

Defense Evasion

Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics’ techniques are cross-listed here when those techniques include the added benefit of subverting defenses.

https://attack.mitre.org/tactics/TA0005

MITRE ATT&CK® Techniques

No Technique Specified

Impacts

Network

Data Source

FortiGate via Syslog or Netflow,Checkpoint via Syslog or Netflow, Palo Alto via Syslog or Netflow

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.

180 seconds

Trigger Conditions

If the following defined pattern/s occur within a 180 second time window.

UnusualIcmp

SubPattern Definitions

SubPattern Name: UnusualIcmp

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

ipProto = 1 AND icmpType NOT IN (0,3,8) AND eventType IN (Group@PH_SYS_EVENT_PermitNetTraffic, Group@PH_SYS_EVENT_NetflowTraffic, Group@PH_SYS_EVENT_BiNetflowTraffic)

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,icmpType

Aggregate Constraint

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

COUNT(*) > 10

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 = UnusualIcmp.srcIpAddr,
 icmpType = UnusualIcmp.icmpType,
 incidentCount = UnusualIcmp.COUNT(*)