Excessive SNMP Port 161 Traffic from a Source to the same Destination

Rule ID

PH_Rule_Flow_213

Default Status

Enabled

Description

Detects excessive (> 5000 in 3 minutes) SNMP polling traffic on UDP port 161 traffic from the same source to the same destination

Severity

MITRE ATT&CK® Tactics

Collection

Collection consists of techniques adversaries may use to gather information and the sources information is collected from that are relevant to following through on the adversary's objectives. Frequently, the next goal after collecting data is to steal (exfiltrate) the data. Common target sources include various drive types, browsers, audio, video, and email. Common collection methods include capturing screenshots and keyboard input.

https://attack.mitre.org/tactics/TA0009

MITRE ATT&CK® Techniques

T1602.001

Data from Configuration Repository: SNMP (MIB Dump)

Adversaries may target the Management Information Base (MIB) to collect and/or mine valuable information in a network managed using Simple Network Management Protocol (SNMP).

https://attack.mitre.org/techniques/T1602/001

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.

ExcessSNMP

SubPattern Definitions

SubPattern Name: ExcessSNMP

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 = 17 AND destIpPort = 161 AND eventType IN (Group@PH_SYS_EVENT_PermitNetTraffic, Group@PH_SYS_EVENT_NetflowTraffic, Group@PH_SYS_EVENT_BiNetflowTraffic) AND srcIpAddr NOT IN (Group@PH_SYS_APP_ACCELOPS,Group@PH_SYS_DEVICE_FSM)

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,destIpAddr

Aggregate Constraint

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

COUNT(*) > 5000

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 = ExcessSNMP.srcIpAddr,
 destIpAddr = ExcessSNMP.destIpAddr,
 incidentCount = ExcessSNMP.COUNT(*)

FortiSIEM Rules