Complete technique description
Adversaries may abuse Unix shell commands and scripts for execution. Unix shells are the primary command prompt on Linux, macOS, and ESXi systems, though many variations of the Unix shell exist (e.g. sh, ash, bash, zsh, etc.) depending on the specific OS or distribution.[DieNet Bash][Apple ZShell] Unix shells can control every aspect of a system, with certain commands requiring elevated privileges.
Unix shells also support scripts that enable sequential execution of commands as well as other typical programming operations such as conditionals and loops. Common uses of shell scripts include long or repetitive tasks, or the need to run the same set of commands on multiple systems.
Adversaries may abuse Unix shells to execute various commands or payloads. Interactive shells may be accessed through command and control channels or during lateral movement such as with Remote Services. Adversaries may also leverage shell scripts to deliver and execute multiple commands on victims or as part of payloads used for persistence.
Within Industrial control system networks, workstations, control servers, hypervisors, networking devices, and embedded devices that run on linux platforms may allow for Unix command shell access or stripped-down shells to implement a subset of commands. Industrial automation equipment generally does not offer command shells as a native user interface.
Official technique definition · Open in the interactive matrix
Parent and sub-techniques
Related pages are navigation context. Their tools, rules and lab results are not automatically inherited.
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.
Command Execution · source-mapped
DC0064 collection page — Collect process command lines and relevant shell/interpreter audit; shell history alone is neither complete nor tamper-resistant.
Providers and collection configuration
- Enable Script Block Logging through the policy/configuration for the installed edition. Forward Microsoft-Windows-PowerShell/Operational for Windows PowerShell, or PowerShellCore/Operational for PowerShell 7.
- Retain script-block ID and fragment ordering alongside process creation. Protect access to collected script text; secrets may be included.
- On Linux, use narrowly scoped Audit execution rules for the lab account and supported architectures, and retain joined SYSCALL/EXECVE/PATH records.
Required normalized fields: interpreter, command_line, actor_uid, session_id.
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": "DC0064",
"collector": "illustrative-lab-collector",
"observation": {
"interpreter": "/bin/sh",
"command_line": "printf LAB_TELEMETRY_CHECK",
"actor_uid": 1000,
"session_id": "lab-session-1"
}
}
Visibility limits: Script content and process command lines are different signals. Logging may be partial, fragmented, filtered or disabled; never assume a command line reveals everything executed.
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.
Process Creation · source-mapped
DC0032 collection page — Collect Sysmon ProcessCreate (1); preserve ProcessGuid and parent identifiers. Security 4688 is an alternative with separate audit/command-line settings.
Providers and collection configuration
- Microsoft Sysmon: Windows event-based collection; enable the event types needed below.
- Linux Audit: Linux alternative for supported system-call and file events; different semantics and fields.
- Apple Endpoint Security clients: macOS alternative where the subscribed event exists; requires an entitled, approved client, not an iOS collector.
- On a disposable Windows host, review the installed Sysmon schema and current configuration; merge scoped event filters into the existing policy rather than replacing it.
- Forward Microsoft-Windows-Sysmon/Operational to the lab collector. Preserve event ID, timestamp, computer, process identifiers and the original event.
- For Linux or macOS, select the equivalent sensor separately and test its emitted fields; a Windows event ID does not transfer across platforms.
Required normalized fields: process_guid, image, parent_image, command_line, user.
<EventFiltering>
<ProcessCreate onmatch="include">
<Image condition="is">C:\Windows\System32\whoami.exe</Image>
</ProcessCreate>
</EventFiltering>
This fragment only selects the named process. It is not a complete production policy. Inspect the installed schema with sysmon64 -s; preserve existing rules, then apply the reviewed complete configuration with sysmon64 -c <configuration-file>.
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": "DC0032",
"collector": "illustrative-lab-collector",
"observation": {
"process_guid": "lab-process-001",
"image": "C:\\Windows\\System32\\whoami.exe",
"parent_image": "C:\\Windows\\System32\\cmd.exe",
"command_line": "whoami",
"user": "LAB\\analyst"
}
}
Visibility limits: Event filtering and sensor versions change coverage. High-volume image-load and process-access collection needs tuning; endpoint events alone do not establish 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 T1701.003 Unix Shell; 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.