T1053 - Scheduled Task/Job

Adversaries may abuse task scheduling functionality to facilitate initial or recurring execution of malicious code. Utilities exist within all major operating systems to schedule programs or scripts to be executed at a specified date and time. A task can also be scheduled on a remote system, provided the proper authentication is met (ex: RPC and file and printer sharing in Windows environments). Scheduling a task on a remote system typically may require being a member of an admin or otherwise privileged group on the remote system.(Citation: TechNet Task Scheduler Security)

Adversaries may use task scheduling to execute programs at system startup or on a scheduled basis for persistence. These mechanisms can also be abused to run a process under the context of a specified account (such as one with elevated permissions/privileges). Similar to System Binary Proxy Execution, adversaries have also abused task scheduling to potentially mask one-time execution under a trusted system process.(Citation: ProofPoint Serpent)

Atomic Tests:

Currently, no tests are available for this technique.

Detection

Monitor scheduled task creation from common utilities using command-line invocation. Legitimate scheduled tasks may be created during installation of new software or through system administration functions. Look for changes to tasks that do not correlate with known software, patch cycles, etc.

Suspicious program execution through scheduled tasks may show up as outlier processes that have not been seen before when compared against historical data. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as network connections made for Command and Control, learning details about the environment through Discovery, and Lateral Movement.

Shield Active Defense

Admin Access

Modify a user’s administrative privileges.

Changing the target system to allow or disallow users to perform tasks requiring administrator level permissions gives the defender leverage in inhibiting or facilitating attacks. The procedures for changing these permissions vary across different operating and software systems.

Opportunity

There is an opportunity to study the adversary and collect first-hand observations about them and their tools.

Use Case

A defender can enable Admin Access on a system to see if the adversary utilizes that access to create scheduled tasks to launch their malware or tools.

Procedures

Remove an account’s administrative access from a system or service to require an adversary to reveal techniques for elevating privileges in order to accomplish certain tasks. Grant an account administrative access to a system or service to enable an adversary to take advantage of those privileges if they compromise the system or service.