Suspicious RDP ActiveX Client Loadededit

Identifies suspicious Image Loading of the Remote Desktop Services ActiveX Client (mstscax), this may indicate the presence of RDP lateral movement capability.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*
  • winlogbeat-*
  • logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Lateral Movement

Version: 100 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guideedit


Rule queryedit

any where (event.category == "library" or (event.category == "process"
and event.action : "Image loaded*")) and (dll.name : "mstscax.dll" or
file.name : "mstscax.dll") and /* depending on noise in your env
add here extra paths */ process.executable : (
"C:\\Windows\\*", "C:\\Users\\Public\\*",
"C:\\Users\\Default\\*", "C:\\Intel\\*", "C:\\PerfLogs\\*",
"C:\\ProgramData\\*", "\\Device\\Mup\\*", "\\\\*" ) and
/* add here FPs */ not process.executable :
("C:\\Windows\\System32\\mstsc.exe",
"C:\\Windows\\SysWOW64\\mstsc.exe")

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 100 (8.5.0 release)
  • Formatting only
Version 6 (8.4.0 release)
  • Updated query, changed from:

    library where dll.name : "mstscax.dll" and /* depending on noise in
    your env add here extra paths */ process.executable : (
    "C:\\Windows\\*", "C:\\Users\\Public\\*",
    "C:\\Users\\Default\\*", "C:\\Intel\\*", "C:\\PerfLogs\\*",
    "C:\\ProgramData\\*", "\\Device\\Mup\\*", "\\\\*" ) and
    /* add here FPs */ not process.executable :
    ("C:\\Windows\\System32\\mstsc.exe",
    "C:\\Windows\\SysWOW64\\mstsc.exe")
Version 4 (8.2.0 release)
  • Formatting only
Version 3 (7.12.0 release)
  • Updated query, changed from:

    library where file.name == "mstscax.dll" and /* depending on noise
    in your env add here extra paths */ wildcard(process.executable,
    "C:\\Windows\\*",
    "C:\\Users\\Public\\*",
    "C:\\Users\\Default\\*",
    "C:\\Intel\\*", "C:\\PerfLogs\\*",
    "C:\\ProgramData\\*",
    "\\Device\\Mup\\*", "\\\\*") and
    /* add here FPs */ not process.executable in
    ("C:\\Windows\\System32\\mstsc.exe",
    "C:\\Windows\\SysWOW64\\mstsc.exe")
Version 2 (7.11.2 release)
  • Formatting only