Remote Services: Remote Desktop Protocol

Adversaries may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user.

Remote desktop is a common feature in operating systems. It allows a user to log into an interactive session with a system desktop graphical user interface on a remote system. Microsoft refers to its implementation of the Remote Desktop Protocol (RDP) as Remote Desktop Services (RDS).[1]

Adversaries may connect to a remote system over RDP/RDS to expand access if the service is enabled and allows access to accounts with known credentials. Adversaries will likely use Credential Access techniques to acquire credentials to use with RDP. Adversaries may also use RDP in conjunction with the Accessibility Features or Terminal Services DLL for Persistence.[2]

ID: T1021.001
Sub-technique of:  T1021
Platforms: Windows
System Requirements: RDP service enabled, account in the Remote Desktop Users group
Contributors: Matthew Demaske, Adaptforward
Version: 1.2
Created: 11 February 2020
Last Modified: 07 August 2023

Procedure Examples

ID Name Description
G0006 APT1

The APT1 group is known to have used RDP during operations.[3]

G0022 APT3

APT3 enables the Remote Desktop Protocol for persistence.[4] APT3 has also interacted with compromised systems to browse and copy files through RDP sessions.[5]

G0087 APT39

APT39 has been seen using RDP for lateral movement and persistence, in some cases employing the rdpwinst tool for mangement of multiple sessions.[6][7]

G0096 APT41

APT41 used RDP for lateral movement.[8][9]

G0001 Axiom

Axiom has used RDP during operations.[10]

G0108 Blue Mockingbird

Blue Mockingbird has used Remote Desktop to log on to servers interactively and manually copy files to remote hosts.[11]

C0015 C0015

During C0015, the threat actors used RDP to access specific network hosts of interest.[12]

C0018 C0018

During C0018, the threat actors opened a variety of ports to establish RDP connections, including ports 28035, 32467, 41578, and 46892.[13]

S0030 Carbanak

Carbanak enables concurrent Remote Desktop Protocol (RDP) sessions.[14]

G0114 Chimera

Chimera has used RDP to access targeted systems.[15]

G0080 Cobalt Group

Cobalt Group has used Remote Desktop Protocol to conduct lateral movement.[16]

S0154 Cobalt Strike

Cobalt Strike can start a VNC-based remote desktop server and tunnel the connection through the already established C2 channel.[17][18]

S0334 DarkComet

DarkComet can open an active screen of the victim’s machine and take control of the mouse and keyboard.[19]

G0035 Dragonfly

Dragonfly has moved laterally via RDP.[20]

G0051 FIN10

FIN10 has used RDP to move laterally to systems in the victim environment.[21]

G1016 FIN13

FIN13 has remotely accessed compromised environments via Remote Desktop Services (RDS) for lateral movement.[22]

G0037 FIN6

FIN6 used RDP to move laterally in victim networks.[23][24]

G0046 FIN7

FIN7 has used RDP to move laterally in victim environments.[25]

G0061 FIN8

FIN8 has used RDP for lateral movement.[26]

G0117 Fox Kitten

Fox Kitten has used RDP to log in and move laterally in the target environment.[27][28]

G1001 HEXANE

HEXANE has used remote desktop sessions for lateral movement.[29]

S0434 Imminent Monitor

Imminent Monitor has a module for performing remote desktop access.[30]

S0283 jRAT

jRAT can support RDP control.[31]

G0094 Kimsuky

Kimsuky has used RDP for direct remote point-and-click access.[32]

S0250 Koadic

Koadic can enable remote desktop on the victim's machine.[33]

G0032 Lazarus Group

Lazarus Group malware SierraCharlie uses RDP for propagation.[34][35]

G0065 Leviathan

Leviathan has targeted RDP credentials and used it to move through the victim environment.[36]

G0059 Magic Hound

Magic Hound has used Remote Desktop Services to copy tools on targeted systems.[37][38]

G0045 menuPass

menuPass has used RDP connections to move across the victim network.[39][40]

S0385 njRAT

njRAT has a module for performing remote desktop access.[41]

G0049 OilRig

OilRig has used Remote Desktop Protocol for lateral movement. The group has also used tunneling tools to tunnel RDP into the environment.[42][43][9]

G0040 Patchwork

Patchwork attempted to use RDP to move laterally.[44]

S0192 Pupy

Pupy can enable/disable RDP connection and can start a remote desktop session using a browser web socket client.[45]

S0583 Pysa

Pysa has laterally moved using RDP connections.[46]

S0262 QuasarRAT

QuasarRAT has a module for performing remote desktop access.[47][48]

S0379 Revenge RAT

Revenge RAT has a plugin to perform RDP access.[49]

S0461 SDBbot

SDBbot has the ability to use RDP to connect to victim's machines.[50]

S0382 ServHelper

ServHelper has commands for adding a remote desktop user and sending RDP traffic to the attacker through a reverse SSH tunnel.[51]

G0091 Silence

Silence has used RDP for lateral movement.[52]

C0024 SolarWinds Compromise

During the SolarWinds Compromise, APT29 used RDP sessions from public-facing systems to internal servers.[53]

G0088 TEMP.Veles

TEMP.Veles utilized RDP throughout an operation.[54]

S0670 WarzoneRAT

WarzoneRAT has the ability to control an infected PC using RDP.[55]

G0102 Wizard Spider

Wizard Spider has used RDP for lateral movement and to deploy ransomware interactively.[56][57][58][59]

S0350 zwShell

zwShell has used RDP for lateral movement.[60]

S0412 ZxShell

ZxShell has remote desktop functionality.[61]

Mitigations

ID Mitigation Description
M1047 Audit

Audit the Remote Desktop Users group membership regularly. Remove unnecessary accounts and groups from Remote Desktop Users groups.

M1042 Disable or Remove Feature or Program

Disable the RDP service if it is unnecessary.

M1035 Limit Access to Resource Over Network

Use remote desktop gateways.

M1032 Multi-factor Authentication

Use multi-factor authentication for remote logins.[62]

M1030 Network Segmentation

Do not leave RDP accessible from the internet. Enable firewall rules to block RDP traffic between network security zones within a network.

M1028 Operating System Configuration

Change GPOs to define shorter timeouts sessions and maximum amount of time any single session can be active. Change GPOs to specify the maximum amount of time that a disconnected session stays active on the RD session host server.[63]

M1026 Privileged Account Management

Consider removing the local Administrators group from the list of groups allowed to log in through RDP.

M1018 User Account Management

Limit remote user permissions if remote access is necessary.

Detection

ID Data Source Data Component Detects
DS0028 Logon Session Logon Session Creation

Monitor for user accounts logged into systems associated with RDP (ex: Windows EID 4624 Logon Type 10). Other factors, such as access patterns (ex: multiple systems over a relatively short period of time) and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP.

Monitoring logon and logoff events for hosts on the network is very important for situational awareness. This information can be used as an indicator of unusual activity as well as to corroborate activity seen elsewhere.

Could be applied to a number of different types of monitoring depending on what information is desired. Some use cases include monitoring for all remote connections and building login timelines for users. Logon events are Windows Event Code 4624 for Windows Vista and above, 518 for pre-Vista. Logoff events are 4634 for Windows Vista and above, 538 for pre-Vista.

Analytic

filtered_logons = filter logon_events where ( (event_id = "4624") AND user NOT IN TOP30(user))

Logon Session Metadata

Monitor authentication logs and analyze for unusual access patterns. A remote desktop logon, through RDP, may be typical of a system administrator or IT support, but only from select workstations. Monitoring remote desktop logons and comparing to known/approved originating systems can detect lateral movement of an adversary.

Analytic

suspicious_logon = filter logons where (event_id = "4624" AND AuthenticationPackageName = 'Negotiate' AND Severity = "Information" AND logon_type = "10")

DS0029 Network Traffic Network Connection Creation

Monitor for newly constructed network connections (typically over port 3389) that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP.

Network Traffic Flow

Monitor network traffic for uncommon data flows that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP).

The Remote Desktop Protocol (RDP), built in to Microsoft operating systems, allows a user to remotely log in to the desktop of another host. It allows for interactive access of the running windows, and forwards key presses, mouse clicks, etc. Network administrators, power users, and end-users may use RDP for day-to-day operations. From an adversary’s perspective, RDP provides a means to laterally move to a new host. Determining which RDP connections correspond to adversary activity can be a difficult problem in highly dynamic environments, but will be useful in identifying the scope of a compromise.Remote Desktop can be detected in several ways

  • Network connections to port 3389/tcp (assuming use of the default port)
  • Packet capture analysis
  • Windows security logs (Event ID 4624, 4634, 4647, 4778)
  • Detecting network connections from mstsc.exe
  • Execution of the process rdpclip.exe
  • Runs as the clipboard manager on the RDP target if clipboard sharing is enabled

Analytic 1

rdp_start = filter flow_start where (port == "3389")rdp_end = filter flow_start where (port == "3389")rdp = group flow_start, flow_end by src_ip, src_port, dest_ip, dest_port

DS0009 Process Process Creation

Monitor for newly executed processes (such as mstsc.exe) that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions that spawn additional processes as the logged-on user.

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