Complete technique description
Adversaries may target devices that are transient across ICS networks and external networks. Normally, transient assets are brought into an environment by authorized personnel and do not remain in that environment on a permanent basis. [North American Electric Reliability Corporation June 2021] Transient assets are commonly needed to support management functions and may be more common in systems where a remotely managed asset is not feasible, external connections for remote access do not exist, or 3rd party contractor/vendor access is required.
Adversaries may take advantage of transient assets in different ways. For instance, adversaries may target a transient asset when it is connected to an external network and then leverage its trusted access in another environment to launch an attack. They may also take advantage of installed applications and libraries that are used by legitimate end-users to interact with control system devices.
Transient assets, in some cases, may not be deployed with a secure configuration leading to weaknesses that could allow an adversary to propagate malicious executable code, e.g., the transient asset may be infected by malware and when connected to an ICS environment the malware propagates onto other systems.
Official technique definition · Open in the interactive matrix
Detection telemetry and configuration
These contracts are selected through exact technique-to-data-component relationships or explicitly labelled planning overrides. Configure a collector at the relevant observation point; a telemetry name alone is not coverage.
Application Log Content · source-mapped
DC0038 collection page — Select the application event family required by the detection and document its native schema before normalization.
Providers and collection configuration
- Enable the application audit category or instrument the owned lab application at the authorization/action boundary.
- Define a schema with timestamp, service, actor, object, action, result and correlation ID. Export structured records through an authenticated collector.
- Redact secrets and personal content, separate audit from debug logs, set retention and verify delivery during rotation/restart.
Required normalized fields: service, action, actor, record_count, result.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0038",
"collector": "illustrative-lab-collector",
"observation": {
"service": "lab-portal",
"action": "export_requested",
"actor": "lab-reader",
"record_count": 3,
"result": "authorized"
}
}
Visibility limits: Debug output is not necessarily a durable audit trail. Application developers must emit the relevant event; installing a log pipeline does not make an absent event exist.
Logon Session Creation · source-mapped
DC0067 collection page — Enable Audit Logon and collect successful session creation on the receiving host; join session/logon IDs rather than only account names.
Providers and collection configuration
- Use a lab-only GPO under Computer Configuration → Windows Settings → Security Settings → Advanced Audit Policy Configuration. Enable the specific subcategory named below.
- For object-level auditing, configure a narrow system access control list (SACL) on the test object in addition to policy. Do not audit an entire production directory by default.
- Forward Security events from the responsible host or controller; retain subject and target identities, object identifiers, result and original XML. Confirm effective policy with auditpol /get /category:*.
Required normalized fields: account, logon_id, logon_type, source_ip.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0067",
"collector": "illustrative-lab-collector",
"observation": {
"account": "LAB\\analyst",
"logon_id": "0x12345",
"logon_type": 3,
"source_ip": "192.0.2.10"
}
}
Visibility limits: A policy checkbox alone does not guarantee an event. Host role, SACL, success/failure selection and audit policy precedence matter. Directory changes may arrive as multiple records.
Network Traffic Flow · source-mapped
DC0078 collection page — Collect Zeek conn.log, Suricata flow events or exporter equivalents, including observation point and sampling settings.
Providers and collection configuration
- Zeek: Connection and protocol metadata from traffic visible to the sensor.
- Suricata EVE: Configured flow, alert, DNS, HTTP, TLS and protocol records.
- AWS VPC Flow Logs: IP traffic metadata alternative; no packet payload or DNS answer history, and some traffic is not logged.
- Use an authorized lab TAP/SPAN, virtual mirror or gateway interface. Define which traffic crosses it; avoid assuming visibility into every segment.
- Enable the required Zeek analyzers or Suricata EVE event types. Export logs with sensor identity, clock synchronization and flow correlation identifiers.
- Monitor capture loss, truncation and exporter sampling. Capture payload only with approval and restrictive retention; encryption normally prevents plaintext inspection.
Required normalized fields: source_ip, destination_ip, destination_port, protocol, bytes_sent, bytes_received.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0078",
"collector": "illustrative-lab-collector",
"observation": {
"source_ip": "192.0.2.10",
"destination_ip": "198.51.100.20",
"destination_port": 443,
"protocol": "tcp",
"bytes_sent": 128,
"bytes_received": 512
}
}
Visibility limits: Flows are not packet payloads. NAT, asymmetric routes, encryption, missing mirrors and sampling can hide attribution or content. A destination connection alone does not prove malicious intent.
Simulation design and documented procedures
Atomic evidence: no compatible candidate in this snapshot. Live lab status: not run for these imported procedures.
Use a process simulator or isolated test rig with no connection to production controllers or physical actuators. Preserve safety interlocks; destructive effects require synthetic evidence, not real equipment damage.
No compatible Atomic procedure is present in this pinned evidence set. Technical feasibility has not been ruled out. A custom procedure must define the behavior, target, collection point, success observable and rollback before execution.
Technique-specific experiment contract
- Choose one procedure implementing T0864 Transient Cyber Asset; identify the observable behavior in the source definition, not just its tactic.
- Record exact target, tool/version, inputs, privileges, network limits and approval. Never run an imported default target automatically.
- Enable the collection sources above and verify a benign baseline reaches the detector.
- Run only the approved isolated scenario; capture native events and an independent behavior observable.
- Evaluate the exact rule/model, restore the lab, and preserve configuration, event hashes, alerts, controls and misses.