Thursday, 29 September 2016

Introduction to Malwares



The term malware came from “Malicious software”. It is the software designed to damage, disturb and disrupts normal operations or to steal data. There are different types of malwares. The four main types are
1.   Virus: A virus is a malware attached to another program. Typically a virus requires human interaction to spread. It can be attached with an email or any other shared file.
2.   Worm: A worm is similar to virus. It will not attached to another program and comes as standalone program. It can be automatically spread by using the weaknesses in the operating system
3.   Adware: Adware is a software which will generate a popup window periodically to buy some products or some service. Even though it is harmless, will be annoying for users.
4.   Spyware:  Usually offers something free, and will ask to complete a survey and when you click the submit button it will execute. It can be used to steal information from your system.
5.   Trojan: A Trojan comes as helpful program and may provide some helpful functions. But in the background it will do the malicious activity.
6.   Rootkits: A rootkit is a type of software designed to hide the fact that an operating system has been compromised, sometimes by replacing vital executables. Rootkits allow viruses and malware to “hide in plain sight” by disguising as necessary files that your antivirus software will overlook. A rootkit operates at the kernel level and very hard to find for an Antivirus.
7.   Ransomware: It is a kind of malware that will lock or encrypt files and demands payment to decrypt.
8.   Botnets: Botnet is the short for robot and network, as they do human activities like sending mails, browse web etc. A bot combined with the virus can send email as you from your system.
Protecting System from Malware
                            To protect from malware you should install an antivirus to your system. Antivirus is the software used to remove malwares. Most antivirus uses the definition files, which are the list of all known malware. Each vendor will update their definition files periodically. Because of these updates you should update your antivirus to get the latest definition files. Antivirus checks any newly downloaded program to ensure that it is malware-free. It periodically scans the computer to detect and defeat any malware that might have slipped through.
  There are so many antivirus vendors like popular Norton, Kaspersky, McAfee, Malwarebytes etc. You can choose the desired one based on the resource usage and other options they provide.

     One of the most popular ways to spread malware is by email, which may be disguised to look as if it is from a familiar company such as a bank, or a personal email from a friend. So personal vigilance also required to protect against the malware.
                There are so many free rootkit removal tools like Kaspersky TDSSkiller, Malwarebytes anti rootkit etc. available in the internet. You can run them frequently along with the antivirus.


Limiting User Rights
                          Least privilege is a key component of protecting against any malware, including ransomware. If users don’t need admin rights to their systems, don’t give it to them. That way, malware may not even be able to run on their system since most types must be executed. Limiting file system access on network shares to Read for data that users don’t need to make changes to will prevent ransomware from encrypting those files. Eliminating shares that are open to all, or worse, allow anonymous access, is always recommended, but can reduce the scope of damage ransomware could cause.
Backup
   Always take the backup of your important files to alternate location like external storage or cloud storage like OneDrive or google drive.

Tuesday, 27 September 2016

Introduction to cloud computing



             Cloud computing is the delivery of on-demand computing resources like applications, infrastructure etc. over the Internet on a pay-for-use basis. There are so many vendors provides cloud services like Amazon Web Services (AWS), Microsoft Azure, Google cloud services etc. The term ‘Public Cloud’ is used to refer such services. A private cloud on the other hand will be directly managed by the business entity.


Infrastructure as a service (IaaS)
       Infrastructure as a service provides companies with computing resources including servers, networking, storage, and data center space on a pay-per-use basis. You can manage the OS,Applications and data.
The benefits of IaaS
  • No need to invest in your own hardware
  • It enables you to quickly configure network resources hosted by someone else.
  • Infrastructure scales on demand to support dynamic workloads
  • You can subscribe new or unsubscribe existing service based on demand
Platform as a service (PaaS)
   It enables you to access a software development platform hosted in the cloud. Here you manage only the applications and data. The OS, Network and storage will be manged by the cloud provider.
The benefits of PaaS
  • Develop applications and get to market faster
  • Deploy new web applications to the cloud in minutes
Software as a service (SaaS)
Cloud-based applications run on distant computers that are owned and operated by others and that connect to user computers via the Internet and, usually, a web browser. Office 365, Adobe creative cloud etc are examples of SaaS.
The benefits of SaaS. It will be completely managed by the vendor.
  • You can sign up and rapidly start using innovative business apps
  • Apps and data are accessible from any connected computer
  • No data is lost if your computer breaks, as data is in the cloud
  • The service is able to dynamically scale to usage needs
   You can opt for public cloud, if your requirements are dynamic and client connections are from many different locations. If your requirements are limited or you have a single or limited site offices, it is better to have an in-house data center. As cloud relies on Internet, if you have issues with internet connectivity, all your cloud based services will not be accessible.

Saturday, 24 September 2016

Introduction to Virtualization



                      Virtualization is the act of making virtual version of something like server, desktop, storage or network. It make use of the existing actual hardware to be distributed among different operating system or applications.
                                If we virtualize our servers we can save lot of power by using single physical server for different roles as virtual machines in that physical server. Another advantage is the hardware consolidation. The number of hardware devices need to be take care of will be minimized using virtualization. Also virtualization makes the system recovery easy, as the virtual machine resides as a single file in the host machine. You can copy the virtual machines and thus it makes it easy to setup similar server roles through duplication.
                                   The thing which manages and runs the virtual machine is called as a hypervisor. There are two types of hypervisors, type1 and type2. Type1 or bare metal hypervisor boots up as a virtualization OS. VMware ESXi is an example for that.Type2 or host based hypervisor runs as an application inside the host operating system. Microsoft Hyper-V or VMware workstation are examples of that. VMware, Microsoft and Citrix are the major vendors providing hypervisors. Microsoft Hyper-V comes with windows 7 onwards as an installable option. Oracle gives a completely free hypervisor called VirtualBox.
        Let us create a virtual machine using VMware workstation.

1.   Click on create new virtual machine.

2.   Choose typical and Click Next.

You can choose the source of installation files here. I am choosing my downloaded redhat Linux iso image.
3.   Click Next and provide the username and password.

4.   Click Next and name your os and choose the location where you want to store the VM.

5.   Click Next and enter the hard disk space required for the VM. Even though I gave 20GB it will not use the entire space in the physical disk right now. It will use the disk space on demand up to 20GB. This is called thin provisioning.

6.   Click Finish and check the box power on virtual machine after creation.

You can click customize hardware to change the memory, virtual switch, processor etc.

When the virtual machine power on, it will start the installation of Redhat Linux.