An Access database is a Microsoft database file, usually created with Access and stored as a local .mdb or .accdb file. It is often used by small teams to keep business records such as payroll, customer lists, inventory, or tax-related data. Because it is easy to build and store on a shared drive or endpoint, it can become a hidden repository for sensitive information.
In cyber security, Access databases matter because they are attractive targets for extortion, theft, and internal abuse. A stolen file may expose personal data, banking details, accounting history, or login notes in a format that is easy to copy but hard to notice in monitoring tools. Attackers may search for these files during ransomware intrusions or data theft, then use them as leverage in leak campaigns. Defenders reduce risk by inventorying where Access files live, limiting who can read or export them, encrypting sensitive databases, and moving critical records to systems with stronger access control and auditing.