Microsoft Defender AV must randomize scheduled task times.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-278659 | WNDF-AV-000055 | SV-278659r1190748_rule | CCI-002624 | medium |
| Description | ||||
| In Microsoft Defender Antivirus, randomize the start time of the scan to any interval from 0 to 23 hours. By default, scheduled tasks begin at a random time within four hours of the time specified in Task Scheduler. | ||||
| STIG | Date | |||
| Microsoft Defender Antivirus Security Technical Implementation Guide | 2026-02-17 | |||
Details
Check Text (C-278659r1190748_chk)
Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Randomize scheduled task times is set to "Enabled"; otherwise, this is a finding.
Procedure: Use the Windows Registry Editor to navigate to the following key:
HKLM\Software\Policies\Microsoft\Windows Defender
Criteria: If the value "RandomizeScheduleTaskTimes" is REG_DWORD = 1, this is not a finding.
If the value is 0, this is a finding.
Fix Text (F-83098r1190747_fix)
Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Randomize scheduled task times to "Enabled".