Quick math on the terminal

Hey there! Just this past week I stumbled on a HN comment from 2019. The commenter was fiddling with some scripts to perform some simple math directly on the (bash) terminal. TLDR: Click here to go to the code and skip the backstory. What the commenter proposed was something like this, based on the dc command (comments are mine). $ . calc.sh # Load functionality $ * 4 5 # Multiply 4 and 5 20 $ / 21 3 # Divide 21 by 3 7 This sounded interesting. [Read More]

Using libfuzzer in autotools compiled projects

Hey there. These days I've been playing with libfuzzer, a tool that comes with clang compiler and that allows us to fuzz a program compiled with clang. The fuzzing consists on passing (pseudo-)random data as program input and check if that breaks. To do this with libfuzzer, it is required to define in the program a function called LLVMFuzzerTestOneInput that accepts a buffer of bytes as argument. Then libfuzzer will call this function in a loop with different data. [Read More]

Tricks to improve console programs usability

Hi folks. In this post I goint to present you some tricks that, in my experience, allow to greatly improve the usability of the console programs. I write them down here to avoid to forget them and in the hope that they can be useful to other people. The key is to make the programs simple, which normally is not as easy as it sounds, but I hope these tricks will help you to achieve that. [Read More]

Virus and Python

This post will explain several issues when it comes to understanding how a virus works. They will first be explained what they are and how is its life cycle. The main techniques for detecting a virus will be outlined below. After, the main anti-antivirus techniques will be discussed. Then, it will be explained how a virus works by providing examples of code, to finally add various enhancements and protections so that it cannot be detected by signature. [Read More]

Heap analysis with radare2

Hi everyone. In this post, I'm going to show you how radare2 can be used to perform heap analisys in the glibc. My purpose is to create a reference with examples, that shows what can be done in radare2. I do this cause I haven't found too much info about this on internet, only the heap module presentation made by n4x0r in the r2con 2016. However, I prefer text, so I'll write here the commands with examples, ready to be consulted and copypasted. [Read More]
pwn  heap  radare2