Potential SharpRDP Behavior

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Identifies potential behavior of SharpRDP, which is a tool that can be used to perform authenticated command execution against a remote target via Remote Desktop Protocol (RDP) for the purposes of lateral movement.

Rule type: eql

Rule indices:

  • logs-endpoint.events.process-*
  • logs-endpoint.events.registry-*
  • logs-endpoint.events.network-*

Severity: high

Risk score: 73

Runs every: 5m

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

Maximum alerts per execution: 100

References:

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Lateral Movement
  • Data Source: Elastic Defend

Version: 106

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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/* Incoming RDP followed by a new RunMRU string value set to cmd, powershell, taskmgr or tsclient, followed by process execution within 1m */

sequence by host.id with maxspan=1m
  [network where host.os.type == "windows" and event.type == "start" and process.name : "svchost.exe" and destination.port == 3389 and
   network.direction : ("incoming", "ingress") and network.transport == "tcp" and
   source.ip != "127.0.0.1" and source.ip != "::1"
  ]

  [registry where host.os.type == "windows" and process.name : "explorer.exe" and
   registry.path : ("HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\RunMRU\\*") and
   registry.data.strings : ("cmd.exe*", "powershell.exe*", "taskmgr*", "\\\\tsclient\\*.exe\\*")
  ]

  [process where host.os.type == "windows" and event.type == "start" and
   (process.parent.name : ("cmd.exe", "powershell.exe", "taskmgr.exe") or process.args : ("\\\\tsclient\\*.exe")) and
   not process.name : "conhost.exe"
   ]

Framework: MITRE ATT&CKTM