This Blog URL Has Changed – Please Update Your Readers

Things have been quite on the blog for while. There is a LOT of code being cranked out at the moment as we work towards some deadlines in the summer on various projects. Our team name has also changed from the Connected Information Security Group (CISG) to the Microsoft IT Information Security Tools Team. This…


CAT.NET New Build –

Mainly small bug fixes and a new feature to export the findings into an Excel spreadsheet. Download link is –  We recommend all users to upgrade to this version. We have some work now starting on new features including general performance improvements, UI improvements and rules maintenance. We expect these to be complete by…


Getting Help for CAT.NET and Anti-XSS

We now have a discussion forum for users of CAT.NET. There is no official support for these tools but you can ask questions and we will try to help wherever we can! CAT.NET – Anti-XSS –


MSDN Webcast: Software Security with Static Code Analysis Using CAT.NET (Level 200)

Event Overview In this webcast, we provide an overview of what static code analysis is and typical coding errors that static analysis can and cannot detect. We also look at the recently released CAT.NET tool and how it helps with the detection of security flaws. Presenter: Andreas Fuchsberger, Senior Software Design Engineer, Microsoft Corporation Register…


Current Memory Limitations of CAT.NET

Hi, Andreas Fuchsberger here….. It is important to understand what happens CAT.NET builds its Call Flow Super Graphs. We use a CCI object called CciControlGraph to build a Control Flow Graph for each method and each method call we find in the Common Intermediate Language (CIL) of the modules being analysed. These individual control flow…


Merlin: Better Specifications for CAT.NET

Guest post by Ben Livshits of Microsoft Research here…. In the last several years we have seen a proliferation of static (and sometimes runtime) analysis tools for finding web application vulnerabilities. Companies such as Fortify, Ouncelabs, Klockwork, and others have been selling tools for finding security flaws for a while now. Most focus of the…


Security Code Review Using CAT.NET – Part 2

Hi Andreas Fuchsberger here again…… How does CAT.NET work? As I mentioned in Part 1 here, CAT.NET is an information-flow type static analysis tool using an implementation of tainted-variable analysis. Tainted-variable analysis is an integrity problem in which that tries to identify whether less-trusted data obtained from the user might influence other data that the…


Security Code Review Using CAT.NET – Part 1

Hi Andreas Fuchsberger here … To coincide with the CTP release of CAT.NET and Anti-XSS, within the CSIG we have been taking a long hard look at static analysis tools for developers and Information Security professionals. Over the next series of blog posts I will explain the fundamentals of the techniques used for a code…


CAT.NET CTP Links Are Live Again!

Download CAT.NET CTP (32 bit here and 64 bit here) Anti-XSS was not affected but for completeness Download Anti-XSS 3.0 Beta (here and source code here) Our sincere apologies.