Tetrane's BLOG
Analyzing CVE-2015-0350 with REVEN
In this article we will show how we analyzed and tamper the PoC for CVE-2015-0350, an Adobe Flash vulnerability located in the parsing of JPEG-XR images, with the help of timeless analysis. With REVEN v1.5.0, from an input file causing a crash, we analyze the vulnerability by instantly time-traveling to...
Reversing DirtyC0W
Everybody keeps in mind the Dirtyc0w Linux kernel bug. For those who don’t, take some time to refresh your memory here. The kernel race condition is triggered from user-space and can easily lead a random local user to write into any root owned file. In this article, we will demonstrate...
Unfolding obfuscated code with Reven (part 2)
Last time, by abstracting the runtime effect of the first virtual machine, we have reduced the challenge to a simpler but semantically equivalent program. Its control flow graph has a unique entry point as the basic block starting at 0x402048, whereas ones at 0x4023d4 and at 0x40266e are exit points...
Reversing Windows 7 BSoD display
In this post we’ll try to reverse Windows 7 BSoD using REVEN Axion in order to generate an image from memory and port accesses. Find which video mode is used As a first step, we will need to know which [video mode][wiki-output-caps] is used by the BSoD. To achieve this...
Unfolding obfuscated code with Reven (part 1, full write-up)
In this article, we present a reverse engineering task performed using Reven. This is the full write-up corresponding to a first overview published in October. The binary examined here is F4b_XOR_W4kfu, the challenge scoring the highest number of points over all categories (cryptography, exploit, reverse engineering, etc.) in Grehack 2015’s...
Unfolding obfuscated code (part 1)
01 Oct 2016
by
tdta, Fred, Mathieu, Benoit
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Technical
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Reverse Engineering
Deobfuscation
ctf
Reven
This article is the first one in a series of two. We present an overview of some reverse engineering capabilities of REVEN-Axion, applied to a publicly available challenge, namely F4b_XOR_W4kfu, the most valued at Grehack 2015’s CTF contest (500 points). A more detailed write-up will be published soon for those interested....
Making your own REVEN Axion plugin step by step
In this article we will shed light on REVEN Axion’s customisation possibilities by describing step by step how to create a simple plugin. Percent plugin in action on push edi. We will walk you through: The specification of our plugin The basics of plugin API for REVEN Axion The implementation...
SWF file unpacking with REVEN
Source: wikimedia commons Recently we took a look at a new flash player exploit used by the Angler exploit kit. The sample was obfuscated using the well known ‘packing’ technique: the dropped swf file embeds a second stage swf in the form of an encrypted blob that will be decrypted...
REVEN in your toolkit
Reven provides many analysis tools but still might lack some of your favorite tool features. To address this issue we created a Python API to allow you to create and share plugins. We also developed some ourselves to make REVEN’s interaction with external tools possible. Universal debugging The Gnu debugger...
Decoding function arguments
Today I will show you a feature that is pretty useful when analysing an application. We call it the “arguments decoder”, and it displays the content of a function’s arguments when its prototype is known. The latter’s definition can be either extracted from the msdn function and structures, or given...
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