Potential SharpRDP Behavioredit

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.*

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: 7 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.4.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

/* 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.ip != "127.0.0.1" and
source.ip != "::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 mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 7 (8.4.0 release)
  • Formatting only
Version 6 (8.1.0 release)
  • Formatting only
Version 5 (8.0.0 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", "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" ]
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