The “diff” command is a very nice tools in *NIX environments to compare the content of two files. But there are some situations where diff is a pain to use. The classic case is when you need to compare many files from different directory trees (by example two different releases
I published the following diary on isc.sans.org: “Systemd Could Fallback to Google DNS?“. Google is everywhere and provides free services to everyone. Amongst the huge list of services publicly available, there are the Google DNS, well known as 8.8.8.8, 8.8.4.4 (IPv4) and 2001:4860:4860::8888, 2001:4860:4860::8844Â (IPv6)… [Read more]
Recently I upgraded my laptop with the latest Ubuntu release (12.04-LTS). For a few releases, Ubuntu switched from Gnome to Unity and I’m happy to use it since the 11.04 version! I know that this choice has caused a lot of debates between the aficionados of both GUI but it
Infosec guys are lazy people. At least in my case! There is nothing much boring that typing long shell commands or to perform recurrent tasks. After all, computers are made to make our life easier. Let them work for us! UNIX is a wonderful environment. There are plenty ways to
A few months ago, I posted an article about how to add extra logging facilities to the Bash shell. For specific users, it can be useful to have a complete history of their activity on your server (for audit purposes). The first release candidate of Bash 4.1 is available for
The very first version of the UNIX operating system was born in Augustus 1969! Its early name was Multics (“Multiplexed Information and Computing Service“). Years after years new branches started to build a huge family of different operating systems, all of them descending from the same origin. It has always
I’m just back from the last ISACA Belgian Chapter meeting. Topic of today was about the UNIX OS security audit process. A very large topic! The speaker was Sanjay Vaid. For years now, Linux is deployed in business environment. Linux systems can take several forms: applications servers (print, files, web,
On UNIX systems, log files are everywhere. Application are often very verbose (which is good!) but keeping an eye on logs can quickly become a nightmare! I’m a big fan of the tail command, specially the “-f” flag which does not stop the command once the end of file is
For those who still ignore, Bash 4 is out for a few days! Bash is the most used shell on UNIX hosts. Bash has a built-in mechanism to save a log of all commands executed by the user (default in $HOME/.bash_history) but this file belongs to the user itself and
Here is a quick and dirty bash script which will take care of your files integrity. Integrity is a component of the CIA triad, I’ll not come back on this. For a personal project, I should be able to monitor any change in a specific file. I quickly wrote the
