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”
Tag Archives: SmartScreen
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”
Attack Techniques: Encrypted Archives
Tricking a user into downloading and opening malware is a common attack technique, and defenders have introduced security scanners to many layers of the ecosystem in an attempt to combat the technique: With all this scanning in place, attackers have great incentives to try to prevent their malicious code from detection up until the momentContinue reading “Attack Techniques: Encrypted Archives”
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 guess — they return a reputation based on the URL, and the browser will warn/block loadingContinue reading “Cloaking, Detonation, and Client-side Phishing Detection”