Detection rules › Splunk

Remote Access Software Execution (Sysmon)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

Remote access tools are commonly used as legitimate technical support software and may be allowed by application control within a target environment. Adversaries may install and use these tools post-compromise as alternate communications channels for redundant access or as a way to establish an interactive remote desktop session with the target system. They may also be used as a component of malware to establish a reverse connection or back-connect to a service or adversary controlled system. Installation of many remote access tools may also include persistence (ex: the tool's installation routine creates a Windows Service). This use case detects the execution of remote access software known to be used by threat actors

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1219 Remote Access Tools

References

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

id: '13705.20073'
title: Remote Access Software Execution
description: 'Remote access tools are commonly used as legitimate technical support
  software and may be allowed by application control within a target environment.
  Adversaries may install and use these tools post-compromise as alternate communications
  channels for redundant access or as a way to establish an interactive remote desktop
  session with the target system. They may also be used as a component of malware
  to establish a reverse connection or back-connect to a service or adversary controlled
  system. Installation of many remote access tools may also include persistence (ex:
  the tool''s installation routine creates a Windows Service). This use case detects
  the execution of remote access software known to be used by threat actors. - Threat
  Actor Association: Andariel, APT43, FIN7, Muddled Libra, Scattered Spider (aka.
  0ktapus, UNC3944), Scatter Swine - Software Association: ALPHV/BlackCat, AvosLocker,
  BianLian, Black Basta, Clop, Hive, LockBit, Royal, Trigona - Atomics T1219 Test
  #1 Atomics T1219 Test #2 Atomics T1219 Test #3 Atomics T1219 Test #4 Atomics T1219
  Test #5'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
  ("TeamViewer.exe" OR "AnyDesk.exe" OR "LMIIgnition.exe" OR "GoToAssist.exe" OR "ScreenConnect.exe"
  OR "ammyy.exe" OR "RemotePC.exe" OR "NetSupport.exe" OR "UltraViewer_Desktop.exe"
  OR "vncviewer.exe" OR "Splashtop.exe" OR "Supremo.exe" OR "PCICTLUI.exe" OR "QuickAssist.exe") | where
  match(process_name, "(?i)^(TeamViewer\.exe|AnyDesk\.exe|LMIIgnition\.exe|GoToAssist\.exe|ScreenConnect\.exe|ammyy\.exe|RemotePC\.exe|NetSupport\.exe|UltraViewer_Desktop\.exe|vncviewer\.exe|Splashtop\.exe|Supremo\.exe|PCICTLUI\.exe|QuickAssist\.exe)$")|
  table _time, host, user process, process_*, signature_id, parent_* | bin span=1s
  | stats values(*) as * by _time, host '
techniques:
- command-and-control:remote access software
technique_id: 
- T1219
data_category:
- Windows Sysmon
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1219/T1219.md

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<") ("TeamViewer.exe" OR "AnyDesk.exe" OR "LMIIgnition.exe" OR "GoToAssist.exe" OR "ScreenConnect.exe" OR "ammyy.exe" OR "RemotePC.exe" OR "NetSupport.exe" OR "UltraViewer_Desktop.exe" OR "vncviewer.exe" OR "Splashtop.exe" OR "Supremo.exe" OR "PCICTLUI.exe" OR "QuickAssist.exe")

Stage 2: where

| where match(process_name, "(?i)^(TeamViewer\.exe|AnyDesk\.exe|LMIIgnition\.exe|GoToAssist\.exe|ScreenConnect\.exe|ammyy\.exe|RemotePC\.exe|NetSupport\.exe|UltraViewer_Desktop\.exe|vncviewer\.exe|Splashtop\.exe|Supremo\.exe|PCICTLUI\.exe|QuickAssist\.exe)$")

Stage 3: table

| table _time, host, user process, process_*, signature_id, parent_*

Stage 4: bucket

| bin span=1s

Stage 5: stats

| stats values(*) as * by _time, host

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 1 corpus 237 (splunk 224, kusto 13)
process_namematch
  • "(?i)^(TeamViewer\.exe|AnyDesk\.exe|LMIIgnition\.exe|GoToAssist\.exe|ScreenConnect\.exe|ammyy\.exe|RemotePC\.exe|NetSupport\.exe|UltraViewer_Desktop\.exe|vncviewer\.exe|Splashtop\.exe|Supremo\.exe|PCICTLUI\.exe|QuickAssist\.exe)$" corpus 2 (splunk 2)

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
1TERM
1"<EventID>1<"
1"TeamViewer.exe"
1"AnyDesk.exe"
1"LMIIgnition.exe"
1"GoToAssist.exe"
1"ScreenConnect.exe"
1"ammyy.exe"
1"RemotePC.exe"
1"NetSupport.exe"
1"UltraViewer_Desktop.exe"
1"vncviewer.exe"
1"Splashtop.exe"
1"Supremo.exe"
1"PCICTLUI.exe"
1"QuickAssist.exe"