May 26, 2020


Department of CS

Most of the Technologies in the modern time depends upon the Basic Technology called as Cloud Computing. You will have used this technology with or without your knowledge. Just take a simple example of backing up your whatsapp chat details to Google Drive, where Google Drive is an example for cloud technology. Or might you have been used in any simple photo editor apps, where you need to download a feature in order to use it.

So now a question might arise in your mind as to, what actually is Cloud Computing?

Cloud Computing refers to manipulating, configuring, and accessing the hardware and software resources remotely. It offers online data storage, infrastructure, and application. The term Cloud refers to a Network or Internet.  In other words, we can say that Cloud is something, which is present at remote location. Cloud can provide services over public and private networks, i.e., WAN, LAN, MAN or VPN. Applications such as e-mail, web conferencing, customer relationship management (CRM) execute on cloud.


Cloud service providers (CSP) are companies that offer network services, infrastructure, or business applications in the cloud. The cloud services are hosted in a data center that can be accessed by companies or individuals using network connectivity.


There are certain services and models working behind the scene making the cloud computing feasible and accessible to end users.

 Following are the working models for cloud computing:

Deployment Models:

Deployment models define the type of access to the cloud, i.e., how the cloud is located?

Cloud can have any of the four types of access: Public, Private, Hybrid, and Community cloud.

Service Model:

Cloud computing is based on service models. These are categorized into three basic service models which are -

  •  Infrastructure-as–a-Service (IaaS)

IaaS provides access to fundamental resources such as physical machines, virtual machines, virtual storage, etc.

  •  Platform-as-a-Service (PaaS)

PaaS provides the runtime environment for applications, development and deployment tools, etc.

  •  Software-as-a-Service (SaaS)

SaaS model allows to use software applications as a service to end-users


Cloud Computing Architecture:

We can broadly divide the cloud architecture into two parts:

Front End:

               The front end refers to the client part of cloud computing system. It consists of interfaces and applications that are required to access the cloud computing platforms, Example - Web Browser.

Back End:

               The back End refers to the cloud itself. It consists of all the resources required to provide cloud computing services. It comprises of huge data storage, virtual machines, security mechanism, services, deployment models, servers, etc.

Benefits of cloud computing:

  • One can manipulate and configure the applications online at any time.
  •  It does not require to install a software to access or manipulate cloud application.
  •  Cloud Computing offers online development and deployment tools, programming runtime environment through PaaS model.
  •  Cloud resources are available over the network in a manner that provide platform independent access to any type of clients.
  • Cloud Computing is highly cost effective because it operates at high efficiency with optimum utilization. It just requires an Internet connection

Risks related to Cloud Computing:

  • Security and Privacy
  • Lock In
  • Insecure or Incomplete Data Deletion


- Chandan M

2nd BCA




May 23, 2020


Department of CS

Do you know what is meant by virus???

Virus is an abbreviated form of ‘Vital Information Resource Under Seize. Computer virus is a small program that enters into a computer without the knowledge of the user and by replicating itself interferes with the computer.

How does a computer virus find you???

        Sharing music files or photos with other users,

        Visiting an infected web site,

        Opening spam email or an email attachment,

        Downloading free games, media players and other system utilities,

        Installing mainstream software applications without fully reading license agreements etc..

What does a computer virus do???

        Computer viruses are being programmed to harm your

   computer by damaging programs, deleting files or

   reformatting the HDD.

        Others simply replicate themselves or flood a network with traffic, making it impossible to perform any internet activity.

        Even less harmful computer viruses can significantly disturb your systems performance, supping computer memory and causing computer crashes.

What are the symptoms of computer virus???

        Slow computer performance

        Erratic computer behavior

        Unexplained data loss

        Computer restarts on its own

        You see usual error messages

        Strange sounds or music plays from speakers

        The programs disappear from the computer.

Types of computer virus...

  1. Macro Viruses                                          
  2. Memory resident viruses
  3. Overwrite viruses
  4. Direct action viruses
  5. Directory viruses
  6. Multipartite viruses
  7. Fat viruses
  8. Companion viruses
  9. WORMS
  11. Boot infector
  12. Polymorphic viruses


Macro viruses are the viruses infect the files created using some applications or program that contains macros such as .doc .pps .xls and etc... They hide in documents shared through e-mails and other networks. Ex: Relax, bablas, Melisa etc...


They usually fix themselves inside the computer memory. They get activated every time the OS runs and end up infecting other opened files. They hide in RAM (RANDOM ACCESS MEMORY).

 Ex: CMJ, meve, randex etc…


Torjans can illegally trace important login details of users. For example, in E-banking, they may track your ID’s Passwords etc…



These types of viruses delete any information in a file. They infect files leaving them useless.

Ex: Trj.reboot, way  


They encode and encrypt themselves in different way. They use different encryptions and algorithms.


The Boot Sector Virus or Boot Infectors affects the booting process of the computer system. The boot infectors will inversely affect the hard disk of the computer. Many computer viruses and their effect can damage the computer system.

Top 10 most destructive computer viruses:

  1. Melissa
  2. Storm Worm
  3. Red Code
  4. Red Code ll
  5. Nimda
  6. SQL Slammer virus or Sapphire
  7. My Doom
  8. Sasser and Netsky
  9. Leap-A or Oompa-A
  10. The Kelz virus

CREEPER VIRUS Worlds first computer virus...

Creeper was an experimental self-replicating program written by Bob Thomas at BBN Technologies in 1971.Creeper used the ARPANET to infect DEC PDP-10 computers running the TENEX operating system. Creeper gained access via the ARPANET and copied itself to the remote system where the message, "I'm the creeper, catch me if you can!" was displayed


 Antivirus is a software which detects and removes the viruses from the computer system. Antivirus software typically runs as a background process. It scans the computers, servers or mobile devices to detect and restrict the spread of malware. Many antivirus software programs include real-time threat detection and protection to guard against potential vulnerabilities as they happen. They also perform system scans that monitor device and system files looking for possible risks.


 - Chandan M

2nd BCA