RPC (Remote Procedure Call) to the Internetedit

Detects network events that may indicate the use of RPC traffic to the Internet. RPC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector.

Rule type: query

Rule indices:

  • filebeat-*

Severity: high

Risk score: 73

Runs every: 5 minutes

Searches indices from: now-6m (Date Math format, see also Additional look-back time)

Maximum signals per execution: 100

Tags:

  • Elastic
  • Network

Version: 3 (version history)

Added (Elastic Stack release): 7.6.0

Last modified (Elastic Stack release): 7.7.0

Rule queryedit

network.transport:tcp and destination.port:135 and
source.ip:(10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) and not
destination.ip:(10.0.0.0/8 or 127.0.0.0/8 or 172.16.0.0/12 or
192.168.0.0/16 or "::1")

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 3 (7.7.0 release)

Updated query, changed from:

network.transport: tcp and destination.port: 135 and (
network.direction: outbound or ( source.ip: (10.0.0.0/8 or
172.16.0.0/12 or 192.168.0.0/16) and not destination.ip: (10.0.0.0/8
or 172.16.0.0/12 or 192.168.0.0/16) ) )
Version 2 (7.6.1 release)
  • Removed auditbeat-*, packetbeat-*, and winlogbeat-* from the rule indices.