Adversaries may abuse task scheduling functionality to facilitate initial or recurring execution of malicious code. On Android and iOS, APIs and libraries exist to facilitate scheduling tasks to execute at a specified date, time, or interval. On Android, the `WorkManager` API allows asynchronous tasks to be scheduled with the system. `WorkManager` was introduced to unify task scheduling on Android, using `JobScheduler`, `GcmNetworkManager`, and `AlarmManager` internally. `WorkManager` offers a lot of flexibility for scheduling, including periodically, one time, or constraint-based (e.g. only when the device is charging).(Citation: Android WorkManager) On iOS, the `NSBackgroundActivityScheduler` API allows asynchronous tasks to be scheduled with the system. The tasks can be scheduled to be repeating or non-repeating, however, the system chooses when the tasks will be executed. The app can choose the interval for repeating tasks, or the delay between scheduling and execution for one-time tasks.(Citation: Apple NSBackgroundActivityScheduler)