LSE Blog

We are a little unsure what the robots fascination with Star Trek is but it would seem from the amount of accesses this image has been getting that it holds something interesting for them. Can you figure out what it is? http://i.imgur.com/MjYUJ.gif stego is an animated image (GIF) made from a Star Trek sequence. The first task was to learn more...

simple is a binary that waits for a string on stdin and returns whether the input was the valid key or not. It does that in a very interesting way: there are only 112 bytes of executable x86 code in this 45K binary. After a bit of static analysis in IDA we found out that these 112 bytes implement a common One Instruction Set Computer virtual...

Can you go with the flow? no_mo_flo is a reverse engineering challenge from this year’s PlaidCTF. It’s a 64-bit executable that reads 32 characters from stdin, and tells you if this is the correct flag or not (classic). Opening it in IDA reveals that it takes the input and breaks it into two 16 bytes buffers: for ( i = 0; i...

For the seventh year, we are going to give a 3 day conference to show the work we are doing here at the LSE, about various themes we like, have encountered or overall judge interesting. The exact planning and subjects addressed will be announced later, as well as the exact timetable. As we did last year, we are also opening the talks to external...

One cool way to get your hands dirty when discovering something is to try to make it do simple stuff in some stupid/overkill way. When I first had “fun” with the Linux ELF format, I was told to call printf without using it directly, by finding which address to call from inside the binary. For this, one would start from the mapped program header,...

Prologue Three Devices for logic analysis of passively captured traces, Seven for inter-chip communication driven by hardwired interfaces, Nine for in-circuit debugging limited to specific purpose, One for complex hardware hacking scenarios. Three tinkerers took those words as they are. Overthrown by the complexity implied by the multiplicity of...

Our schedule for the LSE Week 2016 is out ! The schedule will be as follow: July, Thursday the 14th all day long July, Friday the 15th in the evening July, Saturday the 16th all day long The complete schedule is available on the page dedicated to the event

For the sixth year, we are organising the LSE Summer Week mid-July to show the work we are doing here at the LSE, about various themes we like, have encountered or overall judge interesting. The exact planning and subjects addressed will be announced later, as well as the exact timetable. As we did last year, we are also opening the talks to...

There was 3 challenges in the mobile category. Let’s see how we solved them. Ill Intentions Ill Intentions 150 points Do you have have ill intentions? file: illintentions.apk For this first one, we have an apk and some allusions to the intent system used on android. Let’s start by testing it a little in an emulator! $...

The LSE-PC aims to be a compact IBM-PC compatible development board based on an Intel 80386SX CPU and an Altera Cyclone IV EP4CE22E22 FPGA in order to emulate a custom chipset. The main goal of this project is to create a simple, debuggable and customisable version of the well-known PC hardware architecture. Its purpose is mainly didactic for...