SHA-1 Certificates Blocked By Authenticode

Twitter started to light up a bit tonight with folks who are having problems with signatures; both third-party ISVs: … and even Microsoft’s own SysInternals utilities show1 an error: Developers are surprised to see their workflow suddenly broken and wonder why. The problem is outlined here – the tl;dr is that you must use a SHA256-signedContinue reading “SHA-1 Certificates Blocked By Authenticode”

Authenticode in 2016

Last month, I noticed that my eToken USB code-signing key only supports SHA1 and not SHA256. I began hunting for a replacement that can sign using the stronger hash. Fortunately, I didn’t have to look far—the Yubico YubiKey 4 is $40 and supports SHA256, RSA 4096, and ECC p384. Beyond supporting stronger algorithms, it seems toContinue reading “Authenticode in 2016”

Certificates Matter

Recently, my web host stopped supporting the FrontPage Server Extensions used by Microsoft Expression Web 4 for website publishing (FPSE is now out-of-support). FPSE allowed me to publish to my site over a HTTPS connection, helping keep my password safe and my uploaded files unmodified. Unfortunately, the alternative FTP transport is completely insecure–passwords and dataContinue reading “Certificates Matter”

Security Response Basics

Security response isn’t just about the “sexy” analysis of vulnerabilities, reverse-engineering of malware, and so on… it’s probably mostly about getting the basics right. Every morning, I forward all of the PayPal phishing scams I receive to PhishTank, Netcraft, and Spoof@Paypal. Today, I took a closer look at the response I got to the lastContinue reading “Security Response Basics”

DLL Hijacking Just Won’t Die

The folks that build the NSIS Installer have released updates to mitigate a serious security bug related to DLL loading. (v2.5 and v3.0b3 include the fixes). To make a long and complicated story short, a bad guy who exploits this vulnerability places a malicious DLL into your browser’s Downloads folder, then waits. When you run an installerContinue reading “DLL Hijacking Just Won’t Die”

Hashes and Code-Signing

I’ve written a few articles about using Authenticode to sign your code to help prevent attacks, increase user confidence, and reduce interference from security software like Windows SmartScreen. You can read the overview, discussion of code-signing tokens, and “tricks” you can use to shoot yourself in the foot by adding data to a file withoutContinue reading “Hashes and Code-Signing”

Viewing HTTPS Handshakes in Fiddler

You can easily use Fiddler to evaluate what algorithms a client is using to connect to a HTTPS server in Fiddler. First, adjust Fiddler’s configuration using Tools > Fiddler Options to enable capture of CONNECT tunnels but disable decryption: Disabling decryption is necessary because Fiddler decrypts traffic using a HTTPS man-in-the-middle technique, which means thatContinue reading “Viewing HTTPS Handshakes in Fiddler”

Duct Tape and Baling Wire–Cookie Prefixes

Update: Cookie Prefixes are supported by Chrome 49, Opera 36, and Firefox 50. Test page; no status from the Edge team.  A new cookie feature called SameSite Cookies has been shipped by Chrome, Firefox and Edge; it addresses slightly different threats. When I worked on Internet Explorer, we were severely constrained on development resources. WhileContinue reading “Duct Tape and Baling Wire–Cookie Prefixes”