Kernel-Level File Access Control and Audit Logging for Windows

ByStorm Software, founded in 2003 and based in Magnolia, Texas, sells file security software for Windows environments under the FileSure name. Its customers are organizations that must be able to prove who touched which file: financial institutions, healthcare facilities, critical infrastructure operators, government agencies, law firms, universities, and manufacturers. The company reports more than 200 customer organizations across six continents, ranging from small offices to estates with thousands of managed endpoints.

FileSure operates at the Windows kernel level, intercepting file operations before they happen rather than inspecting the damage afterward. Policy defines what actions are permitted on which files, by which users, and through which programs, so unauthorized reads, writes, renames, and mass encryption are refused outright. Because the control is behavioral rather than signature-based, a ransomware variant nobody has catalogued yet is stopped on the same rules, with no zero-day signature update required first.

The same driver produces a tamper-proof audit trail recording who accessed what, when, and using which application, which is the evidence side of HIPAA, PCI DSS, FISMA, SOX, NERC-CIP, and CJIS obligations, and it blocks copying to USB devices for data leak prevention. Three editions ship: FileSure Defend for organizations with IT staff and 20 or more users, managed centrally through Active Directory; FileSure Cloud, pre-configured for small businesses with no IT department; and FileSure for MSPs, which integrates with ConnectWise, NinjaOne, Kaseya, and Datto. Support spans Windows XP through Windows 11.