Private KSN (hereinafter also referred to as KPSN) lets you use your own local reputation database to check the reputation of objects (files or web addresses). The reputation of an object added to the local reputation database has a higher priority than one added to KSN/KPSN. For example, imagine that Kaspersky Endpoint Security is scanning a computer and requests the reputation of a file in KSN/KPSN. If the file has an "untrusted" reputation in the local reputation database but has a "trusted" reputation in KSN/KPSN, Kaspersky Endpoint Security will detect the file as "untrusted" and will take the action defined for detected threats.
However, in some cases Kaspersky Endpoint Security might not request the reputation of an object in KSN/KPSN. If this is the case, Kaspersky Endpoint Security will not receive data from the local reputation database of KPSN. Kaspersky Endpoint Security might not request the reputation of an object in KSN/KPSN for the following reasons:
Kaspersky applications are using offline reputation databases. Offline reputation databases are designed to optimize resources during operation of Kaspersky applications and to protect critically important objects on the computer. Offline reputation databases are created by Kaspersky experts based on data from Kaspersky Security Network. Kaspersky applications update offline reputation databases with anti-virus databases of the specific application. If offline reputation databases contain information about an object being scanned, the application does not request the reputation of this object from KSN/KPSN.
Scan exclusions (trusted zone) are configured in the application settings. If this is the case, the application does not take into account the reputation of the object in the local reputation database.
KSN/KPSN. If this is the case, the application might not request the reputation of previously scanned objects.
To optimize its workload, the application scans files of a certain format and size. The list of relevant formats and size limits are determined by Kaspersky experts. This list is updated with the application's anti-virus databases. You can also configure scan optimization settings in the application interface, for example, for the File Threat Protection component.