Application allowlisting

Most endpoint protection works by identifying bad software. Allowlisting reverses the logic: define what is good and block the rest. This stops unknown malware, unapproved remote access tools and many attacker utilities from executing at all, even when they have no known signature.

Allowlisting is one of the most effective controls against ransomware and appears in several government frameworks. The Canadian Centre for Cyber Security's Top 10 IT security actions include application allowlisting, and the Australian Essential Eight lists application control as a core strategy.

The trade-off is administrative effort. Allowlisting requires an inventory of legitimate software and a process for approving new applications. For that reason, small businesses often start with high-value, stable systems such as servers, point-of-sale terminals, kiosks and machines that control production equipment. Tools like Windows Defender Application Control and AppLocker, often managed through Intune, can enforce rules. Begin in audit mode to see what would be blocked before switching to enforcement.