Security Notes

Satish Tiwary's picture

Linux Antivirus and Virus Scanning

linux and antivirus

Antivirus for Linux Machine.

  • Is there any Virus for linux?
  • Is there any Anti-virus for linux?
  • How to install antivirus on linux?
  • How to scan and update antivirus on linux?
  • How to launch antivirus in linux?
  • How many type of antivirus updates?
  • How to scan our folders,files or drives in linux in cui mode?
  • How to terminate the scanning process?

First Let me wish you all readers " Happy New Year". Thanx for your all love and Support.

Sarath Pillai's picture

fingerprinting-detect remote operating system

OS fingerprinting

In this post we will try to analyze and study one of the first initial steps taken by an intruder to gain access to a network. We will see its implications & how to prevent the intruder from collecting such information.

We will be discussing Fingerprinting in this post. Operating system finger printing and network scanning is generally the first step taken by most of the intruder to gain access. The more information the intruder, has about your network, the more easy it becomes for them to achieve a successful break-in.

Sarath Pillai's picture

shred command usage and examples for deleting files securely in linux

delete files securely in linux

Whenever you delete a file under Linux or any other operating system, the operating system does not remove the data of that file completely from the hard disk. There are several things that an operating system does whenever you ask it to delete a file. If you want to understand how a file deletion works then getting some basic understanding of inodes in Linux is very much necessary.

Many open source forensic tools are freely available on the internet which can be used to retrieve lost or deleted data from the hard disk. Many of them are so easy to use and are graphical, that normal desktop users can also simply download them and retrieve data.

Sarath Pillai's picture

security checklist for a linux system administrator

linux security checklist

Security of any operating system is one of the primary responsibilities of any Linux system administrator. I must say that, its also one of the toughest tasks, for a Linux system administrator. You cannot be very certain, that the machine that's under you is a secure machine(there exists no machine on the internet, which can be called as completely secure).

Oh yeah..You can make your machine, the most secure machine in the world, just by pulling out the Network Interface Cable(Joking...).

Although it was just a joke, if you think a bit deeper you will come to know, that its quite true. You cant make a system completely secure. Because just imagine the number security patches, a software vendor roles out each and everyday(Thanks to open source community, as they are doing a great job in this area).

Sarath Pillai's picture

How Does File Deletion work in Linux

file deletion in linux

Although we create,delete, modify a number of files on the system everyday, the system does a lot of operations behind that simple thing to work. There are different operations done by the operating system, on the file system, whenever a file is deleted or created. I have tried to explain the main data structure behind files called inodes, in my post Inodes and its structure in Linux

In this post we will be covering and comparing the below things.


Sarath Pillai's picture

Encrypting a Linux Partition Using LUKS

luks encryption

Red Hat started to implement encryption of the entire file system, from Red Hat Enterprise Linux 6 onwards. This encryption of the entire file system's is a much better way to secure the data on the disk. This is an added advantage for people who are prone to using mobile devices for their day to day work. The main advantage is that, even if the entire disk is lost, your data cannot be easily accessed as it is encrypted and requires a pass phrase key to access the data inside.

Red hat implements this through LUKS.


What is LUKS?


Sarath Pillai's picture

How to Configure Basic Apache Reverse Proxy

reverse proxy and apache server

What is Reverse Proxy in Apache?


To understand reverse proxy we need to think of security in apache. There is no webserver that can be called as a completely secure webserver. And if you have a large website which is very popular and get a lot of requests from the internet, then security is always a headache and concern for the system administrator.

Its the policy of every system administrator to expose as minimum as possible to the Internet. Running all the applications that are completely different from each other in a website in one platform (one server), which is also the main webserver serving requests on the internet is not a good idea. Also increasing performance and loadbalencing the applications available on a website is also important.

The idea is depicted in the below picture.

Sarath Pillai's picture

What are website cookies and how do cookies work

What are cookies in Websites

People in the computer industry must have heard the term "cookie" many times, non-technical people also are aware of the term cookie because of web browser usage. Some say its a privacy threat, and some people are in support of it. In this post we will go and have a look at what really is a cookie? Is cookie a security or privacy threat? how is cookie currently used and implemented? etc.

When and where was cookie developed?

The credit of the first implementation of cookies goes to the same company who came up with SSL/TLS, The source code of their browser in open source is now called Mozilla,they are non other than Netscape Communications.  

Sarath Pillai's picture

Packet Capturing with TCPDUMP command in linux

tcpdump packet capture linux

In this tutorial we will be looking into a very well known tool in Linux system administrators tool box. Some times during troubleshooting this tool proves to be very helpful. With the help of this tool you can analyze the packet before it reaches the application stack. And some times detect why the server is not responding to a ping request, why an application is not responding to a certain machine etc etc.

Sarath Pillai's picture

how to install and configure kerberos server

kerberos in linux

Hi all...In this post we will be installing and configuring kerberos infrastructure. I recommend going through the below posts  as basic requirement for understanding this post.

Needham-Schroeder protocol Explained

What is kerberos and how does kerberos work


Subscribe to RSS - Security Notes