Google Calendar C2 via Script Interpreter

Last updated 12 days ago on 2026-01-30

Created 12 days ago on 2026-01-30

About

Detects a two-stage Google Calendar C2 pattern where a scripting runtime (Node.js, Python, osascript) first connects to calendar.app.google to retrieve a hidden C2 address, then initiates a secondary connection to the decoded C2 host. This sequence is characteristic of packages using Unicode steganography in Google Calendar events to stage dynamic command-and-control endpoints.

Tags

Domain: EndpointOS: macOSUse Case: Threat DetectionTactic: Command and ControlTactic: ExecutionData Source: Elastic DefendLanguage: eql

Severity

high

Risk Score

MITRE ATT&CK™

Command and Control (TA0011)(external, opens in a new tab or window)

↳ Web Service (T1102)(external, opens in a new tab or window)

Execution (TA0002)(external, opens in a new tab or window)

↳ Command and Scripting Interpreter (T1059)(external, opens in a new tab or window)

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-endpoint.events.network-*
Related Integrations: endpoint(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗sequence by process.entity_id with maxspan=20s
  [network where host.os.type == "macos" and event.type == "start" and
    (process.name in ("node", "osascript") or process.name like "python*" or
     process.code_signature.trusted == false or process.code_signature.exists == false) and
    destination.domain like "calendar.app.google*"]
  [network where host.os.type == "macos" and event.type == "start" and destination.domain == null]

Install detection rules in Elastic Security

Detect Google Calendar C2 via Script Interpreter in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).