T1059.007 JavaScript

T1059.007 JavaScript

Sub-technique of: T1059

High-Level Description

Adversaries may abuse various implementations of JavaScript for execution. JavaScript (JS) is a platform-independent scripting language (compiled just-in-time at runtime) commonly associated with scripts in webpages, though JS can be executed in runtime environments outside the browser.

JScript is the Microsoft implementation of the same scripting standard. JScript is interpreted via the Windows Script engine and thus integrated with many components of Windows such as the Component Object Model and Internet Explorer HTML Application (HTA) pages.

JavaScript for Automation (JXA) is a macOS scripting language based on JavaScript, included as part of Apple’s Open Scripting Architecture (OSA), that was introduced in OSX 10.10. Apple’s OSA provides scripting capabilities to control applications, interface with the operating system, and bridge access into the rest of Apple’s internal APIs. As of OSX 10.10, OSA only supports two languages, JXA and AppleScript. Scripts can be executed via the command line utility osascript, they can be compiled into applications or script files via osacompile, and they can be compiled and executed in memory of other programs by leveraging the OSAKit Framework.

Adversaries may abuse various implementations of JavaScript to execute various behaviors. Common uses include hosting malicious scripts on websites as part of a Drive-by Compromise or downloading and executing these script files as secondary payloads. Since these payloads are text-based, it is also very common for adversaries to obfuscate their content as part of Obfuscated Files or Information.

Kill Chain Phase

• Execution (TA0002)

Platforms: Linux, macOS, Windows

What to Check

• Identify if JavaScript technique is applicable to target environment
• Check Linux systems for indicators of JavaScript
• Check macOS systems for indicators of JavaScript
• Check Windows systems for indicators of JavaScript
• Verify mitigations are bypassed or absent (4 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: JScript execution to gather local computer information via cscript

JScript execution test, execute JScript via cscript command. When successful, system information will be written to $env:TEMP\T1059.007.out.txt

Supported Platforms: windows