This policy setting allows you to define the number of days after which a catch-up definition update will be required. By default, the value of this setting is 1 day. If you enable this setting, a catch-up definition update will occur after the specified number of days. If you disable or do not configure this setting, a catch-up definition update will be required after the default number of days. Counter Measure: Configure this setting depending on your organization's requirements. Potential Impact: More frequent definition updates impacts performance. Fix: (1) GPO: Computer Configuration\Administrative Templates\Windows Components\Windows Defender\Signature Updates\Define the number of days after which a catch-up definition update is required (2) REG: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Signature Updates!SignatureUpdateCatchupInterval