Detection rules › Splunk
RDP Connection (Sysmon)
This use case looks for when an RDP network connection has been established
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | |
| Persistence | |
| Lateral Movement |
References
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 3: Network connection |
Rule body
id: '9037.12148'
title: RDP Connection
description: 'This use case looks for when an RDP network connection has been established.
-- Threat Actor Association: Agrius, APT35/Phosphorus/Magic Hound, Daixin Team,
Flax Typhoon, Karakurt, Lapsus$, Muddled Libra, Scattered Spider (aka. 0ktapus,
UNC3944), UNC5221, UTA0178 - Software Association: Akira, AvosLocker, BianLian,
Blackcat/ALPHV, BlackByte, Lockbit, LV, Play, Quantum, Ransom Cartel, Rhysida, Royal,
Snatch, Trigona'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (EventCode=3 OR "Event>ID>3<")
(TERM(3389) OR TERM(RDP)) | table _time, host, user dest, direction, event_id, eventtype,
parent_*, process, process_*, user, user_id, src_*, dest_* | bin span=1s | stats
values(*) as * by _time, host | where match(dest_port, "(?i)3389|rdp") or match(src_port,
"(?i)3389|rdp") '
techniques:
- lateral-movement:remote services:remote desktop protocol
- initial-access:external remote services
technique_id:
- T1021.001
- T1133
data_category:
- Process use of network
- Windows Sysmon
references:
- https://www.group-ib.com/resources/threat-research/silence_moving-into-the-darkside.pdf
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (EventCode=3 OR "Event>ID>3<") (TERM(3389) OR TERM(RDP))
Stage 2: table
| table _time, host, user dest, direction, event_id, eventtype, parent_*, process, process_*, user, user_id, src_*, dest_*
Stage 3: bucket
| bin span=1s
Stage 4: stats
| stats values(*) as * by _time, host
Stage 5: where
| where match(dest_port, "(?i)3389|rdp") or match(src_port, "(?i)3389|rdp")
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
EventCode | eq |
| field:"EventID" kind:eq value:"3" |
dest_port | regex_match |
| field:"DestinationPort" kind:regex_match |
src_port | regex_match |
| field:"SourcePort" kind:regex_match |
Search terms
These SPL tokens match against raw event text.
| Stage | Term |
|---|---|
| 1 | "Event>ID>3<" |
| 1 | 3389 |
| 1 | RDP |