Category: Security

Monitor users activity on Linux system with psacct

We will look into tracking users activities on Linux – CentOS or REL system in particular. psacct is application for monitoring users activities on the system. In many cases you would like to know what was done on the system, while someone else working on it. 1. Lest install psacct utilitie yum install psacct 2.

Install SoftEther server on Linux CentOS 7.2

We will take a look at hot to install SoftEther VPN on CentOS 7 and connect to it from Windows system running VPN manager. 1. We install CentOS 7 minimal with firewalld and selinux disabled. Make sure gcc is installed with all updates yum update -y yum install gcc 2. Download softether-vpnserver* package for Linux

Encrypting home folder on Ubuntu or Linux mint

In this example we will encrypt home directory for user user1. This procedure should work on any Ubuntu system or similar platform like Linux mint. We will need to have administrator user besides user1 to complete the encryption. 1. Create admin user user2 2. Install necessary software if its not yes installed sudo apt-get install

How to deploy ASSP Spam Gateway with Postfix MTA on CentOS 6.4

In this tutorial we will show how to install and configure ASSP spam Gateway with Postfix as MTA on CentOS 6.4. In this particular case this system will be used as spam gateway which will scan incoming and outgoing email for spam and viruses.

Using TLS Encription with Postfix CentOS 6

This tutorial based on CentOS 6.4 Linux Asymmetric encryption uses key pair public and private. With asymmetric encryption we use digital certificates to discover other people public keys. Certificate stores information like Organization name , users email address , department and so on. Before encrypted communication starts one of the party’s sends public certificate to

Protect CentOS Linux system with SELinux

In many cases users simply turn off SELinux due to lack of understanding of this great security feature provided with every RedHat , CentOS , Fedora and some other Linux distributions. Another popular alternative, available on Novell’s SuSE Linux and Canonical’s Ubuntu platform, is called AppArmor. In this article we will take closer look at

RPM Repository security for RedHat and CentOS

RPM packages are frequently organized into repositories. Generally, such repositories include groups of packages with different functions. Security is always a concern when downloading packages over the internet. If hacker penetrate the repository, you have no way of knowing which packages are genuine.

How to setup ssh Keys for authentication without password

In this article we will take a look at how to setup authentication with ssh keys. In our example we have Server names s1 and workstation named w1. Our goal is to setup secure ssh authentication without password. This considered to be a more secure way plus it comes really handy when you need to

Basic ClamAV installation on CentOS 7 and CentOS 6

ClamAV is an open source antivirus engine for detecting trojans, viruses, malware & other malicious threats. ClamAV includes a multi-threaded scanner daemon, command line utilities for on demand file scanning and automatic signature updates. It is one of the most popular virus scanner that run on CentOS and RedHat and here is very simple quick

Deploy IPTABLES with NAT and SURICATA IDS on CentOS 7

IPTABLES with NAT and SURICATA IDS on CentOS 7 In this how to we will look into setting up perimeter firewall on the budget. We will make sure IPTABLES forwards all packets to NFQUEUE for scanning. Nat rules will also be setup to forward packets to internal network from outside. 1. Enable routing vi /etc/sysctl.conf