Detection rules › Splunk
RDP Enabled (PowerShell)
Detects if RDP service has been enabled on Windows host
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | |
| Defense Impairment | |
| Lateral Movement |
References
Telemetry coverage
| Provider | Record / event type |
|---|---|
| PowerShell | Event ID 4104: Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body
id: '1106.1172'
title: RDP Enabled
description: 'Detects if RDP service has been enabled on Windows host -- Threat Actor
Association: APT35/Phosphorus/Magic Hound, DarkSide, BlackMatter, FIN7, TA551, Wizard
Spider, Yanluowang -- Software Association: BianLian, Black Basta, Conti, Hive,
IcedID, Insekt, Lockbit, Nefilim, Ryuk Ransomware, Sodinokibi/REvil'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` signature_id=4104 AND (((TERM(reg)
AND TERM(add)) OR TERM(Set-ItemProperty) ) AND (TERM(fDenyTSConnections) AND "Terminal
Server") AND ((TERM(REG_DWORD) AND TERM(/d) AND TERM(0)) OR (TERM(-value) AND TERM(0))))
OR (TERM(netsh) AND TERM(remote) AND TERM(desktop) AND TERM(enable=yes)) OR (TERM(Enable-NetFirewallRule)
AND TERM(remote) AND TERM(-displaygroup)) | rex field=process mode=sed max_match=0
"s/(?mi)^(Path:(.+)?)|^(ScriptBlock.+)|^(Creating Scriptblock.+)//g"| rex field=process
mode=sed "s/[\n\r]+|\s\s+//g" | table _time, host, user process, signature_id |
bin span=1s | stats values(*) as * by _time, host '
techniques:
- defense-evasion:modify registry
- lateral-movement:remote services:remote desktop protocol
technique_id:
- T1112
- T1021.001
data_category:
- PowerShell logs
- Process command-line parameters
references:
- https://pureinfotech.com/enable-remote-desktop-command-prompt-windows-10/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_powershell` signature_id=4104 AND (((TERM(reg) AND TERM(add)) OR TERM(Set-ItemProperty) ) AND (TERM(fDenyTSConnections) AND "Terminal Server") AND ((TERM(REG_DWORD) AND TERM(/d) AND TERM(0)) OR (TERM(-value) AND TERM(0)))) OR (TERM(netsh) AND TERM(remote) AND TERM(desktop) AND TERM(enable=yes)) OR (TERM(Enable-NetFirewallRule) AND TERM(remote) AND TERM(-displaygroup))
Stage 2: rex
| rex field=process mode=sed max_match=0 "s/(?mi)^(Path:(.+)?)|^(ScriptBlock.+)|^(Creating Scriptblock.+)//g"
Stage 3: rex
| rex field=process mode=sed "s/[\n\r]+|\s\s+//g"
Stage 4: table
| table _time, host, user process, signature_id
Stage 5: bucket
| bin span=1s
Stage 6: stats
| stats values(*) as * by _time, host
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
signature_id | eq |
| field:"signature_id" kind:eq value:"4104" |
Search terms
These SPL tokens match against raw event text.
| Stage | Term |
|---|---|
| 1 | reg |
| 1 | add |
| 1 | "Set-ItemProperty" |
| 1 | fDenyTSConnections |
| 1 | "Terminal Server" |
| 1 | REG_DWORD |
| 1 | "/d" |
| 1 | 0 |
| 1 | "-value" |
| 1 | 0 |
| 1 | netsh |
| 1 | remote |
| 1 | desktop |
| 1 | "enable=yes" |
| 1 | "Enable-NetFirewallRule" |
| 1 | remote |
| 1 | "-displaygroup" |