Potential SharpRDP Behavior

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.*
winlogbeat-*
logs-windows.*

Severity: high

Risk score: 73

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: 4 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 7.16.0

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 event.type
== "start" and process.name : "svchost.exe" and destination.port ==
3389 and network.direction : ("incoming", "ingress") and
network.transport == "tcp" and source.address != "127.0.0.1" and
source.address != "::1" ] [registry where process.name :
"explorer.exe" and registry.path : ("HKEY_USERS\\*\\Software\\Micr
osoft\\Windows\\CurrentVersion\\Explorer\\RunMRU\\*") and
registry.data.strings : ("cmd.exe*", "powershell.exe*", "taskmgr*",
"\\\\tsclient\\*.exe\\*") ] [process where event.type in
("start", "process_started") and (process.parent.name : ("cmd.exe",
"powershell.exe", "taskmgr.exe") or process.args :
("\\\\tsclient\\*.exe")) and not process.name : "conhost.exe" ]

Threat mapping

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Framework: MITRE ATT&CK^TM

Tactic:
- Name: Lateral Movement
- ID: TA0008
- Reference URL: https://attack.mitre.org/tactics/TA0008/
Technique:
- Name: Remote Services
- ID: T1021
- Reference URL: https://attack.mitre.org/techniques/T1021/

Rule version history

edit

Version 4 (7.16.0 release)

Updated query, changed from:

/* 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 event.type
== "start" and process.name : "svchost.exe" and destination.port ==
3389 and network.direction == "incoming" and network.transport ==
"tcp" and source.address != "127.0.0.1" and source.address != "::1"
] [registry where process.name : "explorer.exe" and
registry.path : ("HKEY_USERS\\*\\Software\\Microsoft\\Windows\\Current
Version\\Explorer\\RunMRU\\*") and registry.data.strings :
("cmd.exe*", "powershell.exe*", "taskmgr*", "\\\\tsclient\\*.exe\\*")
] [process where event.type in ("start", "process_started") and
(process.parent.name : ("cmd.exe", "powershell.exe", "taskmgr.exe") or
process.args : ("\\\\tsclient\\*.exe")) and not process.name :
"conhost.exe" ]

Version 2 (7.12.0 release)

Formatting only

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