Command and Scripting Interpreter

Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries. These interfaces and languages provide ways of interacting with computer systems and are a common feature across many different platforms. Most systems come with some built-in command-line interface and scripting capabilities, for example, macOS and Linux distributions include some flavor of [Unix Shell](https://attack.mitre.org/techniques/T1059/004) while Windows installations include the [Windows Command Shell](https://attack.mitre.org/techniques/T1059/003) and [PowerShell](https://attack.mitre.org/techniques/T1059/001).

There are also cross-platform interpreters such as [Python](https://attack.mitre.org/techniques/T1059/006), as well as those commonly associated with client applications such as [JavaScript](https://attack.mitre.org/techniques/T1059/007) and [Visual Basic](https://attack.mitre.org/techniques/T1059/005).

Adversaries may abuse these technologies in various ways as a means of executing arbitrary commands. Commands and scripts can be embedded in [Initial Access](https://attack.mitre.org/tactics/TA0001) payloads delivered to victims as lure documents or as secondary payloads downloaded from an existing C2. Adversaries may also execute commands through interactive terminals/shells, as well as utilize various [Remote Services](https://attack.mitre.org/techniques/T1021) in order to achieve remote Execution.(Citation: Powershell Remote Commands)(Citation: Cisco IOS Software Integrity Assurance - Command History)(Citation: Remote Shell Execution in Python)

Platforms: Linux
macOS
Windows
Network
Office 365
Azure AD
IaaS
Google Workspace
Tactics:
phase_name: execution

Detection:
Command-line and scripting activities can be captured through proper logging of process execution with command-line arguments. This information can be useful in gaining additional insight to adversaries' actions through how they use native processes or custom tools. Also monitor for loading of modules associated with specific languages.

If scripting is restricted for normal users, then any attempt to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent.

Scripts are likely to perform actions with various effects on a system that may generate events, depending on the types of monitoring used. Monitor processes and command-line arguments for script execution and subsequent behavior. Actions may be related to network and system information discovery, collection, or other scriptable post-compromise behaviors and could be used as indicators of detection leading back to the source script.

References:
source_name: mitre-attack
description: Abdou Rockikz. (2020, July). How to Execute Shell Commands in a Remote Machine in Python. Retrieved July 26, 2021.
source_name: Remote Shell Execution in Python
description: Cisco. (n.d.). Cisco IOS Software Integrity Assurance - Command History. Retrieved October 21, 2020.
source_name: Cisco IOS Software Integrity Assurance - Command History
description: Microsoft. (2020, August 21). Running Remote Commands. Retrieved July 26, 2021.
source_name: Powershell Remote Commands