Category Archives: dev

Defensive Technology: Windows Filtering Platform

Last November, I wrote a post about the basics of security software. In that post, I laid out how security software is composed of sensors and throttles controlled by threat intelligence. In today’s post, we’ll look at the Windows Filtering Platform, a fundamental platform technology introduced in Windows Vista that provides the core sensor andContinue reading “Defensive Technology: Windows Filtering Platform”

Runtime Signature Checking Threat Model

Telerik developers recently changed Fiddler to validate the signature on extension assemblies before they load. If the assembly is unsigned, the user is presented with the following message: In theory, this seems fine/good– signing files is a good thing! However, it’s important to understand the threat model and tradeoffs here. Validating signatures every time aContinue reading “Runtime Signature Checking Threat Model”

Authenticode in 2025 – Azure Trusted Signing

I’ve written about signing your code using Authenticode a lot over the years, from a post in 2015 about my first hardware token to a 2024 post about signing using a Digicert HSM. Recently, Azure opened their Trusted Signing Service preview program up for individual users and I decided to try it out. The documentationContinue reading “Authenticode in 2025 – Azure Trusted Signing”

Guidelines for Secure Filename Display

Many years ago, I wrote the first drafts of Chromium’s Guidelines for Secure URL Display. These guidelines were designed to help feature teams avoid security bugs whereby a user might misinterpret a URL when making a security decision. From a security standpoint, URLs are tricky because they consist of a mix of security-critical information (theContinue reading “Guidelines for Secure Filename Display”