Protocol Tunneling T1572
Tactic: Command & Control
Adversaries may tunnel network communications to and from a victim system within a separate protocol to avoid detection/network filtering and/or enable access to otherwise unreachable systems. Tunneling involves explicitly encapsulating a protocol within another. This behavior may conceal malicious traffic by blending in with existing traffic and/or provide an outer layer of encryption (similar to a VPN). Tunneling could also enable routing of network packets that would otherwise not reach their intended destination, such as SMB, RDP, or other traffic that would be filtered by network appliances or not routed over the Internet.
Events covered
22 catalog events are tagged with this technique by at least one rule.
Authoring guide
These 97 rules share fields, values, and exclusions.
Fields filtered most (75 distinct)
These fields appear most often in rule filters.
Top indicator values (533 distinct)
These values appear most often in rule predicates.
Exclusions (244 distinct)
These values appear most often in top-level exclusions.
Rules under this technique
These vendors publish rules tagged with this technique.
Sigma 27 rules
- Cloudflared Tunnel Connections Cleanup
- Cloudflared Tunnel Execution
- Cloudflared Tunnels Related DNS Requests
- Communication To LocaltoNet Tunneling Service Initiated
- Communication To LocaltoNet Tunneling Service Initiated - Linux
- Communication To Ngrok Tunneling Service - Linux
- Communication To Ngrok Tunneling Service Initiated
- DNS Query To Devtunnels Domain
- Network Connection Initiated To BTunnels Domains
- Network Connection Initiated To Cloudflared Tunnels Domains
- Network Connection Initiated To DevTunnels Domain
- Network Connection Initiated To Visual Studio Code Tunnels Domain
- Port Forwarding Activity Via SSH.EXE
- Potential RDP Tunneling Via Plink
- Potential RDP Tunneling Via SSH
- Potentially Suspicious Usage Of Qemu
- Process Initiated Network Connection To Ngrok Domain
- PUA - 3Proxy Execution
- PUA - Ngrok Execution
- RDP Over Reverse SSH Tunnel
- RDP to HTTP or HTTPS Target Ports
- RDP tunneling configuration enabled for port forwarding
- RDP tunneling detected
- RDP tunneling via ngrok detected
- Silence.EDA Detection
- Suspicious Plink Port Forwarding
- Tunneling Tool Execution
Elastic 34 rules
- Curl SOCKS Proxy Activity from Unusual Parent
- Curl SOCKS Proxy Detected via Defend for Containers
- DNS Tunneling
- IPv4/IPv6 Forwarding Activity
- Kubectl Network Configuration Modification
- Linux SSH X11 Forwarding
- Newly Observed IPSEC NAT Traversal Peer
- Port Forwarding Rule Addition
- Potential DNS Exfiltration via Excessive Chunked Queries
- Potential DNS Tunneling via Long and Unique Subdomains
- Potential DNS Tunneling via NsLookup
- Potential ICMP Tunneling Activity to the Internet
- Potential Linux Tunneling and/or Port Forwarding
- Potential Linux Tunneling and/or Port Forwarding
- Potential Linux Tunneling and/or Port Forwarding via Command Line
- Potential Linux Tunneling and/or Port Forwarding via SSH Option
- Potential Linux Tunneling or Port Forwarding via SSH
- Potential Linux Tunneling via Cloudflared
- Potential Network Traffic Tunneling via Proxychains
- Potential Protocol Tunneling via Chisel Client
- Potential Protocol Tunneling via Cloudflared
- Potential Protocol Tunneling via EarthWorm
- Potential Protocol Tunneling via Legit Utilities
- Potential Protocol Tunneling via Yuze
- Potential Remote Desktop Protocol Tunneling
- Potential Remote Desktop Tunneling Detected
- Potential SSH Reverse Port Forwarding
- Potential Traffic Tunneling using QEMU
- Potential Traffic Tunneling with QEMU
- Potential Tunneling via Tailscaled
- ProxyChains Activity
- Suspicious Utility Launched via ProxyChains
- Torsocks Execution
- Tunneling and/or Port Forwarding Detected via Defend for Containers
Splunk 26 rules
- Cisco IOS XE Tunnel Interface Configuration
- Linux Ngrok Reverse Proxy Usage
- Named Pipe Created (Sysmon)
- ngrok Execution - Windows (PowerShell)
- ngrok Execution - Windows (Sysmon)
- ngrok Execution - Windows (Windows Event Log)
- Ngrok Reverse Proxy on Network
- Okta Non-Standard VPN Usage
- Potential ngrok Tunnel - Windows (Windows Event Log)
- QEMU Network Tunneling - Windows (PowerShell)
- QEMU Network Tunneling - Windows (Sysmon)
- QEMU Network Tunneling - Windows (Windows Event Log)
- Scheduled Task with Potential SSH Tunnel - Windows (PowerShell)
- Scheduled Task with Potential SSH Tunnel - Windows (Sysmon)
- Scheduled Task with Potential SSH Tunnel - Windows (Windows Event Log)
- ssh.exe Execution (Sysmon)
- ssh.exe Execution (Windows Event Log)
- Tunneling Process Created (PowerShell)
- Tunneling Process Created (Sysmon)
- Tunneling Process Created (Windows Event Log)
- Windows Ngrok Reverse Proxy Usage
- Windows Potential Cloudflared Network Connection
- Windows Potential Cloudflared Tunnel Execution
- Windows Protocol Tunneling with Plink
- Windows SoftEther VPN Masquerading as Legitimate Binary
- Windows SSH Proxy Command
Kusto 10 rules
- Abnormal Port to Protocol
- Ngrok Reverse Proxy on Network (ASIM DNS Solution)
- Pathlock TDnR - SAP Router Log Events
- Potential Remote Desktop Tunneling
- Tailscale Premium: DERP relay traffic surge
- Tailscale Premium: Subnet router throughput anomaly
- Ubiquiti - Connection to known malicious IP or C2
- Ubiquiti - connection to non-corporate DNS server
- Ubiquiti - Large ICMP to external server
- Ubiquiti - Unusual DNS connection