Defensive Technology: Ransomware Data Recovery

In a prior installment we looked at Controlled Folder Access, a Windows feature designed to hamper ransomware attacks by preventing untrusted processes from modifying files in certain user folders. In today’s post, we look at the other feature on the Ransomware protection page of the Windows Security Center App — Ransomware data recovery. User-Interface TheContinue reading “Defensive Technology: Ransomware Data Recovery”

Security Product Efficacy

I’ve written about security products previously, laying out the framing that security products combine sensors and throttles with threat intelligence to provide protection against threats. As a product engineer, I spend most of my time thinking about how to improve sensors and throttles to enhance protection, but those components only provide value if the threatContinue reading “Security Product Efficacy”

Web Category Filtering

Since the first days of the web, users and administrators have sought to control the flow of information from the Internet to the local device. There are many different ways to implement internet filters, and numerous goals that organizations may want to achieve: Today’s post explores the last of these: blocking content based on category.Continue reading “Web Category Filtering”

Understanding SmartScreen and Network Protection

The vast majority of cyberthreats arrive via one of two related sources: That means that by combining network-level sensors and throttles with threat intelligence (about attacker sites), security software can block a huge percentage of threats. Protection Implementation On Windows systems, that source of network threat information is commonly called SmartScreen, and support for queryingContinue reading “Understanding SmartScreen and Network Protection”

Security Software – An Overview

I’ve spent nearly my entire professional career in software security: designing software to prevent abuse by bad actors. I’ve been battling the bad guys for over two decades now, from hunting security bugs in Microsoft Office (I once won an Xbox for finding a vulnerability that allowed malicious clipart take over your computer) to designingContinue reading “Security Software – An Overview”

Best Practices for SmartScreen AppRep

Last year, I wrote about how Windows integrates SmartScreen Application Reputation to help ensure users have a secure and smooth experience when running downloaded software. tl;dr: When a user runs a downloaded program, a call to SmartScreen’s web-based reputation service is made, and four possible outcomes can occur: As a software developer, it’s natural thatContinue reading “Best Practices for SmartScreen AppRep”

Defensive Technology: Controlled Folder Access

Most client software’s threat models (e.g. Edge, Chrome) explicitly exclude threats where the local computer was compromised by malware. That’s because, without a trusted computing base, it’s basically impossible to be secure against attackers. This concept was immortalized decades ago in the Ten Immutable Laws of Security: In the intervening years, new technologies (like SecureContinue reading “Defensive Technology: Controlled Folder Access”

Defensive Technology: Antimalware Scan Interface (AMSI)

Endpoint security software faces a tough challenge — it needs to be able to rapidly distinguish between desired and unwanted behavior with few false positives and false negatives, and attackers work hard to obfuscate (or cloak) their malicious code to prevent detection by security scanners. To maximize protection, security software wants visibility into attack chainsContinue reading “Defensive Technology: Antimalware Scan Interface (AMSI)”

pushState and URL Blocking

The Web Platform offers a handy API called pushState that allows a website’s JavaScript to change the URL displayed in the address bar to another URL within the same origin without sending a network request and loading a new page. The pushState API is handy because it means that a Web Application can change theContinue reading “pushState and URL Blocking”

Cloaking, Detonation, and Client-side Phishing Detection

Today, most browsers integrate security services that attempt to protect users from phishing attacks: for Microsoft’s Edge, the service is Defender SmartScreen, and for Chrome, Firefox, and many derivatives, it’s Google’s Safe Browsing. URL Reputation services do what you’d expect — they return a reputation based on the URL, and the browser will warn/block loadingContinue reading “Cloaking, Detonation, and Client-side Phishing Detection”