Unauthorized Software


  • presence of known malware is an obvious IoC
    • isn’t always a major crisis
    • but does warrant prompt action to understand risk
  • presence of common attack tools is highly concerning
    • but may be used by security personnel and administrators as part of their job

Unauthorized Scheduled Tasks

  • Scheduled Tasks is a Windows utility designed to allow routine maintenance processes to run in an organized and automated way
    • often used to run backups and maintenance scripts
    • often abused by attackers and malware
      • may use scheduled tasks to
        • automate communication with a C&C server
        • or launch a reverse shell when the system restarts
  • Monitor scheduled tasks for changes and review new items to ensure they are authorized
  • Changes generate an event recorded in the System or Security Event Log
    • contains:
      • task’s name
      • who made the change
      • timestamp
    • Event ID 4698 indicates a scheduled task was created or modified
    • Event ID 4700 indicates a scheduled task was enabled or disabled
    • can search events using keywords
      • e.g., “Task Scheduler”

File System and Registry Changes

  • File system and registry changes can indicate a security breach or attack
  • attacker may change critical system configuration stored in system files or registry keys to change or disable essential security settings or store malware and scripts
  • Indicators:
    • creation of new files or folders in unexpected locations or with unusual names
    • Unexpected or unauthorized changes to files
    • Removing temp files, clearing temp folders, or deleting log entries
    • Changes to registry keys related to security settings
    • Unauthorized changes to user accounts or group membership