Remote System Discovery: Broadcast Discovery

Adversaries may perform broadcast discovery requests to enumerate systems and devices on a network. Broadcast discovery works by one system or device sending messages to all systems and devices on a network (or subnet) and then waiting for a response. If a response is received that means the system or device that responded is live and can communicate over that protocol. Adversaries may leverage different protocols supported on the network for sending broadcast messages.

Some common OT protocols that have broadcast discovery mechanisms are Building Automation and Control Network (BACNet) Who-Is requests, Common Industrial Protocol (CIP) List Identity User Datagram Protocol (UDP) broadcast requests, and Siemens S7 broadcast identification requests.[1][2]

ID: T0846.002
Sub-technique of:  T0846
Tactic: Discovery
Version: 1.0
Created: 20 April 2026
Last Modified: 23 April 2026

Procedure Examples

ID Name Description
C0063 2025 Poland Wiper Attacks

During the 2025 Poland Wiper Attacks, the adversaries used arp to conduct remote system discovery activities.[3]

S1009 Triton

Triton uses a Python script that is capable of detecting Triconex controllers on the network by sending a specific UDP broadcast packet over port 1502. [4]

Targeted Assets

ID Asset
A0008 Application Server
A0007 Control Server
A0009 Data Gateway
A0006 Data Historian
A0017 Distributed Control System (DCS) Controller
A0016 Firewall
A0002 Human-Machine Interface (HMI)
A0005 Intelligent Electronic Device (IED)
A0012 Jump Host
A0018 Programmable Automation Controller (PAC)
A0003 Programmable Logic Controller (PLC)
A0004 Remote Terminal Unit (RTU)
A0014 Routers
A0010 Safety Controller
A0015 Switch
A0011 Virtual Private Network (VPN) Server
A0001 Workstation

Mitigations

ID Mitigation Description
M0930 Network Segmentation

Ensure proper network segmentation is followed to protect critical systems and devices.

M0814 Static Network Configuration

ICS environments typically have more statically defined devices, therefore minimize the use of both IT discovery protocols (e.g., DHCP, LLDP) and discovery functions in automation protocols.[5][6] Examples of automation protocols with discovery capabilities include OPC UA Device Discovery[7], BACnet[8], and Ethernet/IP.[9]

Detection Strategy

ID Name Analytic ID Analytic Description
DET0908 Detection of Broadcast Discovery AN2051

Monitor for anomalies related to discovery related ICS functions, including devices that have not previously used these functions or for functions being sent to many outstations.
Monitor for new ICS protocol connections to existing assets or for device scanning (i.e., a host connecting to many devices) over ICS and enterprise protocols (e.g., ICMP, DCOM, WinRM). For added context on adversary enterprise procedures and background see Remote System Discovery.

References