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)
Cross-Platform Behavioral Detection of Scheduled Task/Job Abuse
User Account Management: User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures:
Enforcing the Principle of Least Privilege
Implementing Strong Password Policies
Managing Dormant and Orphaned Accounts
Account Lockout Policies
Multi-Factor Authentication (MFA) for High-Risk Accounts
Restricting Interactive Logins
Tools for Implementation
Built-in Tools:
Identity and Access Management (IAM) Tools:
Privileged Account Management (PAM):
Operating System Configuration: Operating System Configuration involves adjusting system settings and hardening the default configurations of an operating system (OS) to mitigate adversary exploitation and prevent abuse of system functionality. Proper OS configurations address security vulnerabilities, limit attack surfaces, and ensure robust defense against a wide range of techniques. This mitigation can be implemented through the following measures:
Disable Unused Features:
Enforce OS-level Protections:
Secure Access Settings:
File System Hardening:
Secure Remote Access:
Harden Boot Configurations:
Regular Audits:
Tools for Implementation
Windows:
Linux/macOS:
Cross-Platform:
Restrict File and Directory Permissions: Restricting file and directory permissions involves setting access controls at the file system level to limit which users, groups, or processes can read, write, or execute files. By configuring permissions appropriately, organizations can reduce the attack surface for adversaries seeking to access sensitive data, plant malicious code, or tamper with system files.
Enforce Least Privilege Permissions:
Example (Windows): Right-click the shared folder → Properties → Security tab → Adjust permissions for NTFS ACLs.
Harden File Shares:
Example: Set permissions to restrict write access to critical files, such as system executables (e.g., /bin or /sbin on Linux). Use tools like chown and chmod to assign file ownership and limit access.
On Linux, apply:
chmod 750 /etc/sensitive.conf
chown root:admin /etc/sensitive.conf
File Integrity Monitoring (FIM):
Audit File System Access:
Restrict Startup Directories:
C:\ProgramData\Microsoft\Windows\Start Menu.Example: Restrict write access to critical directories like /etc/, /usr/local/, and Windows directories such as C:\Windows\System32.
icacls "C:\Windows\System32" /inheritance:r /grant:r SYSTEM:(OI)(CI)Flsattr or auditd.Privileged Account Management: Privileged Account Management focuses on implementing policies, controls, and tools to securely manage privileged accounts (e.g., SYSTEM, root, or administrative accounts). This includes restricting access, limiting the scope of permissions, monitoring privileged account usage, and ensuring accountability through logging and auditing.This mitigation can be implemented through the following measures:
Account Permissions and Roles:
Credential Security:
Multi-Factor Authentication (MFA):
Privileged Access Management (PAM):
Auditing and Monitoring:
Just-In-Time Access:
Tools for Implementation
Privileged Access Management (PAM):
Credential Management:
Multi-Factor Authentication:
Linux Privilege Management:
Just-In-Time Access:
Audit: Auditing is the process of recording activity and systematically reviewing and analyzing the activity and system configurations. The primary purpose of auditing is to detect anomalies and identify potential threats or weaknesses in the environment. Proper auditing configurations can also help to meet compliance requirements. The process of auditing encompasses regular analysis of user behaviors and system logs in support of proactive security measures.
Auditing is applicable to all systems used within an organization, from the front door of a building to accessing a file on a fileserver. It is considered more critical for regulated industries such as, healthcare, finance and government where compliance requirements demand stringent tracking of user and system activates.This mitigation can be implemented through the following measures:
System Audit:
Permission Audits:
Software Audits:
Configuration Audits:
Network Audits: