Cross-source coverage

T1133 / ATT&CK

External Remote Services

108 rules · 107 families across 7 sources.

Showing deprecated rules · back to the default

From MITRE ATT&CK 19.2

Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management and VNC can also be used externally.

Access to Valid Accounts to use the service is often a requirement, which could be obtained through credential pharming or by obtaining the credentials from users after compromising the enterprise network. Access to remote services may be used as a redundant or persistent access mechanism during an operation.

Access may also be gained through an exposed service that doesn’t require authentication. In containerized environments, this may include an exposed Docker API, Kubernetes API server, kubelet, or web application such as the Kubernetes dashboard.

Adversaries may also establish persistence on network by configuring a Tor hidden service on a compromised system. Adversaries may utilize the tool ShadowLink to facilitate the installation and configuration of the Tor hidden service. Tor hidden service is then accessible via the Tor network because ShadowLink sets up a.onion address on the compromised system. ShadowLink may be used to forward any inbound connections to RDP, allowing the adversaries to have remote access. Adversaries may get ShadowLink to persist on a system by masquerading it as an MS Defender application.

Platforms
Containers · Linux · macOS · Windows
Telemetry
WinEventLog:SecurityWinEventLog:ApplicationWinEventLog:Sysmonauditd:SYSCALLNSM:ConnectionsNSM:Flowmacos:unifiedlogPF:LogsApplicationLog:APIkubernetes:audit

How MITRE says to detect it DET0354

Behavior-chain detection for T1133 External Remote Services across Windows, Linux, macOS, Containers

Windows Analytic 1004

Unusual or unauthorized external remote access attempts (e.g., RDP, VPN, Citrix) → repeated failed logins followed by a successful session from uncommon geolocations or outside business hours → subsequent internal lateral movement or data exfiltration activities.

  • WinEventLog:Security EventCode=4776, 4625
  • WinEventLog:Application VPN, Citrix, or remote access gateway logs showing external IP addresses
  • WinEventLog:Sysmon EventCode=3, 22

Linux Analytic 1005

Repeated SSH, VPN, or RDP gateway authentication attempts from external IPs → subsequent successful logon → remote shell or lateral movement activity (e.g., scp/sftp).

  • auditd:SYSCALL ssh logins or execve of remote commands
  • NSM:Connections Failed password or accepted password for SSH users
  • NSM:Flow connection: Inbound connections to SSH or VPN ports

macOS Analytic 1006

Unexpected inbound or outbound VNC/SSH/Screen Sharing connections from external sources → repeated failed logins followed by success → remote interactive sessions or abnormal file transfers.

  • macos:unifiedlog Remote login (ssh) or screen sharing authentication attempts
  • macos:unifiedlog Inbound connections to VNC/SSH ports
  • PF:Logs External traffic to remote access services

Containers Analytic 1007

Connections to exposed container services (e.g., Docker API, Kubernetes API server) from unauthorized external IPs → abnormal container creation/start → lateral activity within cluster nodes.

  • ApplicationLog:API Docker/Kubernetes API access from external sources
  • kubernetes:audit Unauthorized container creation or kubelet exec logs
  • NSM:Flow External access to container ports (2375, 6443)

splunk/security_content

35 rules
Detection Severity Format
Cisco Network Interface Modifications Undefined SPL
Confluence Unauthenticated Remote Code Execution CVE-2022-26134 Undefined SPL
Detect attackers scanning for vulnerable JBoss servers Undefined SPL
Detect Exchange Web Shell Undefined SPL
Exchange PowerShell Abuse via SSRF Undefined SPL
Exploit Public Facing Application via Apache Commons Text Undefined SPL
Exploit Public-Facing Fortinet FortiNAC CVE-2022-39952 Undefined SPL
F5 BIG-IP iControl REST Vulnerability CVE-2022-1388 Undefined SPL
Fortinet Appliance Auth bypass Undefined SPL
Hunting for Log4Shell Undefined SPL

+ 25 more from splunk/security_content → showing the 10 highest-severity

elastic/detection-rules

26 rules
Detection Severity Format
AWS Lambda Function URL Created with Public Access High Elastic TOML
Deprecated - SSH Connection Established Inside A Running Container High Elastic TOML
Deprecated - SSH Process Launched From Inside A Container High Elastic TOML
Multiple SonicWall Login Failures Followed by Successful Login High Elastic TOML
RPC (Remote Procedure Call) from the Internet High Elastic TOML
SMB (Windows File Sharing) Activity from the Internet High Elastic TOML
VNC (Virtual Network Computing) from the Internet High Elastic TOML
Accepted Default Telnet Port Connection Medium Elastic TOML
AWS RDS DB Instance Made Public Medium Elastic TOML
Deprecated - SSH Process Launched From Inside A Container via Elastic Defend Medium Elastic TOML

+ 16 more from elastic/detection-rules → showing the 10 highest-severity

Wazuh Core Ruleset

23 rules · 22 families
Detection Severity Format
ASA: Multiple AAA (VPN) authentication failures. High Wazuh XML
Asterisk: Extension enumeration. High Wazuh XML
Asterisk: Extension IAX Enumeration. High Wazuh XML
Asterisk: Multiple failed logins. 2 variants High Wazuh XML
Asterisk: Multiple failed logins. 2 variants High Wazuh XML
Asterisk: Multiple failed logins (user enumeration in process). High Wazuh XML
CiscoVPN: Multiple VPN authentication failures. High Wazuh XML
Netscaler: Multiple http resource access denied High Wazuh XML
Netscaler: Multiple non-http resource access denied High Wazuh XML
PIX: Multiple AAA (VPN) authentication failures. High Wazuh XML

+ 13 more from Wazuh Core Ruleset → showing the 10 highest-severity

SigmaHQ/sigma

20 rules
Detection Severity Format
External Remote SMB Logon from Public IP High Sigma
OpenCanary - RDP New Connection Attempt High Sigma
OpenCanary - SSH Login Attempt High Sigma
OpenCanary - SSH New Connection Attempt High Sigma
OpenCanary - Telnet Login Attempt High Sigma
Potential Exploitation of GoAnywhere MFT Vulnerability High Sigma
Running Chrome VPN Extensions via the Registry 2 VPN Extension High Sigma
Suspicious File Created by ArcSOC.exe High Sigma
Unusual Child Process of dns.exe High Sigma
Unusual File Deletion by Dns.exe High Sigma

+ 10 more from SigmaHQ/sigma → showing the 10 highest-severity

panther-labs/panther-analysis

2 rules
Detection Severity Format
AWS RDS Instance Modified to be Publicly Accessible Critical Panther Python
Wiz Issue WITH SSH to EC2 Instance High Panther Python

Azure/Azure-Sentinel

1 rule
Detection Severity Format
Potential SSH Tunnel to AAD Connect Host Undefined KQL

socfortress/Wazuh-Rules

1 rule
Detection Severity Format
T1133 - External Remote Services via Chrome Extensions Registry Key Creation (Detected: ) · win.eventdata.targetObject = (?i)HKLM\\\\SOFTWARE\\\\WOW6432Node\\\\Google\\\\Chrome\\\\…, win.eventdata.eventType = (?i)^CreateKey High Wazuh XML

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