From the Field: Application Allowlisting

๐Ÿ”Ž ๐—™๐—ฟ๐—ผ๐—บ ๐˜๐—ต๐—ฒ ๐—™๐—ถ๐—ฒ๐—น๐—ฑ โ€” Real-World Findings from Security Assessments

๐Ÿ’ฅ ๐Ÿฑ๐Ÿณ.๐Ÿญ%ย of infrastructures Iโ€™ve assessed ๐—ฑ๐—ผ ๐—ป๐—ผ๐˜ ๐˜‚๐˜€๐—ฒ ๐—ฎ๐—ฝ๐—ฝ๐—น๐—ถ๐—ฐ๐—ฎ๐˜๐—ถ๐—ผ๐—ป ๐—ฎ๐—น๐—น๐—ผ๐˜„๐—น๐—ถ๐˜€๐˜๐—ถ๐—ป๐—ด in their Windows infrastructures.

Application allowlisting is ๐—ผ๐—ป๐—ฒ ๐—ผ๐—ณ ๐˜๐—ต๐—ฒ ๐—บ๐—ผ๐˜€๐˜ ๐—ฒ๐—ณ๐—ณ๐—ฒ๐—ฐ๐˜๐—ถ๐˜ƒ๐—ฒ โ€” yet most overlooked โ€” security measures in Windows infrastructure. Unlike antivirus, EDR, or XDR solutions that rely on detecting known threats, allowlisting takes the opposite approach:

โœ… ๐—œ๐—ณ ๐—ถ๐˜โ€™๐˜€ ๐—ป๐—ผ๐˜ ๐—ฒ๐˜…๐—ฝ๐—น๐—ถ๐—ฐ๐—ถ๐˜๐—น๐˜† ๐—ฎ๐—น๐—น๐—ผ๐˜„๐—ฒ๐—ฑ, ๐—ถ๐˜ ๐˜„๐—ผ๐—ปโ€™๐˜ ๐—ฟ๐˜‚๐—ป.

That means even brand-new malware has a much harder time causing damage. Itโ€™s a proactive control, not a reactive one.

๐—ง๐˜„๐—ผ ๐—ฏ๐˜‚๐—ถ๐—น๐˜-๐—ถ๐—ป ๐—ผ๐—ฝ๐˜๐—ถ๐—ผ๐—ป๐˜€ ๐—ณ๐—ฟ๐—ผ๐—บ ๐— ๐—ถ๐—ฐ๐—ฟ๐—ผ๐˜€๐—ผ๐—ณ๐˜ ๐˜†๐—ผ๐˜‚ ๐—ฐ๐—ฎ๐—ป ๐˜‚๐˜€๐—ฒ ๐˜๐—ผ๐—ฑ๐—ฎ๐˜†:

๐Ÿ”น ๐—”๐—ฝ๐—ฝ๐—Ÿ๐—ผ๐—ฐ๐—ธ๐—ฒ๐—ฟ

Great for user workstations and controlled environments. Itโ€™s easier to set up compared to other solutions, but keep in mind:

โ–ช๏ธ It runs as a service โ€” an admin can stop it.

โ–ช๏ธ Proper allowlisting takes time. Youโ€™ll need to audit your environment to understand what software is actually used (including shadow IT).

โ–ช๏ธ Luckily, Audit Mode lets you simulate enforcement and collect data without disruption.

โ–ช๏ธ Be aware of lolbin bypasses โ€” and check out AaronLocker for a practical starting point.

๐Ÿ”น ๐—ช๐—ถ๐—ป๐—ฑ๐—ผ๐˜„๐˜€ ๐——๐—ฒ๐—ณ๐—ฒ๐—ป๐—ฑ๐—ฒ๐—ฟ ๐—”๐—ฝ๐—ฝ๐—น๐—ถ๐—ฐ๐—ฎ๐˜๐—ถ๐—ผ๐—ป ๐—–๐—ผ๐—ป๐˜๐—ฟ๐—ผ๐—น (๐—ช๐——๐—”๐—–)

A much more robust solution โ€” it operates at the kernel level, meaning policies can be cryptographically signed and enforced even before Windows boots.

โ–ช๏ธ Harder to bypass.

โ–ช๏ธ Ideal for high-security environments.

โ–ช๏ธ More complex to configure, but “recent” wizard-based tools have made it significantly easier to generate secure policies.

๐——๐—ฒ๐˜€๐—ฝ๐—ถ๐˜๐—ฒ ๐—ฏ๐—ฒ๐—ถ๐—ป๐—ด ๐—ณ๐—ฟ๐—ฒ๐—ฒย and built-in, very few organizations use either solution in a meaningful way. Even among those who do, allowlisting is often limited to a single use case โ€” not a full strategy.

If I excluded partial or narrow use cases, the real number is likely closer to ๐Ÿต๐Ÿฌ% ๐˜„๐—ถ๐˜๐—ต๐—ผ๐˜‚๐˜ ๐—ฝ๐—ฟ๐—ผ๐—ฝ๐—ฒ๐—ฟ ๐—ฎ๐—น๐—น๐—ผ๐˜„๐—น๐—ถ๐˜€๐˜๐—ถ๐—ป๐—ด.

๐Ÿ”’ ๐—™๐—ถ๐—ป๐—ฎ๐—น ๐˜๐—ถ๐—ฝ: ๐——๐—ผ๐—ปโ€™๐˜ ๐—ท๐˜‚๐˜€๐˜ ๐—ฏ๐—น๐—ผ๐—ฐ๐—ธ known bad executables. True allowlisting means defining exactly whatโ€™s allowed โ€” everything else should be denied by default.