A paint brush protective cover for a paint brush includes a jacket which provides for wet media storage and safe transportation. Automated malware signature generation includes monitoring incoming unknown files for the presence of malware and analyzing the incoming unknown files based on both a plurality of classifiers of file behavior and a plurality of classifiers of file content. The fluid circuit includes a slow-release device for releasing differential pressure, thereby slowly displacing the load as a function of flow from the fluid source. The content may vary depending upon which party is accessing the code.