computer virus

computer virus

A computer virus is a piece of software that attaches itself to another program to corrupt the program and files on the computer system.
Types of Computer Virus
Computer Viruses are classified according to their nature of infection and behavior. Different types of computer virus classification are given below.
1. Resident virus: 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.Examples CMJ,Randex,Mrklunky etc.
 2. Overwrite Virus: These types of viruses delete any information in a file they infect, leaving them partially or completely useless once they are infected. Once in the computer, they replace all the file content but the file size doesn’t change.examples trivial.88.D,trj.Reboot etc
3. \Boot sector: A Boot Sector Virus infects the first sector of the hard drive, where the Master Boot Record (MBR) is stored. . If a computer is infected with Boot Sector Virus, when the computer is turned on, the virus launches immediately and is loaded into memory, enabling it to control the computer. examples poly boot,AntiEXE,stone virus,disk killer,form etc
4. Macro virus: Macro viruses infect files that are created using certaing applications e.g ms office suite, these macros are usually stored as part of the document or spreadsheet and can travel to other systems when these files are transferred to another computer.examples Relax,Bablas etc
5. Directory Virus: Also known as cluster virus or file system virus. They infect the computer’s directory by changing the path indicating file location. They are usually located in the disk but affect the entire directory. Example is any file with the extension .EXE or .COM 3
6. \Polymorphic virus: Polymorphic Viruses have the capability to change their appearance and change their code every time they infect a different system.This helps the Polymorphic Viruses to hide from anti-virus software.examples are Elkern,Marburg,etc.
Effects of virus
It causes computer to crash (i.e. to stop functioning normally or to stop responding to other software) Loss of files and corruption of data stored in file.
Virus warning signs 
When a computer is infected with virus, the following symptoms may occur
 Slow system performance
 Presence of tiny dots
 Incomplete saving of files
 Appearance of strange characters
  Corruption of the system set up instructions
 Wandering across the screen
 New windows keep opening up at an alarming rate
 when files and folders getting deleted
  when disks and drives are not working properly
 Sources of Virus
  Infected storage devices such as flash drive ,CD-ROM etc
 By downloading or opening attachments in email from unknown source
 Through internet download
 Installation of infected programs
  opening an infected document
  by downloading cracked and illegal versions of software

MALWARE PROGRAMS
Malware is an abbreviated term meaning malicious software.it is a program that is specifically designed to gain access to or damage the computer files without the knowledge of the owner. It is developed for the purpose of doing harm to files, software and hardware.Computer Virus is one of the examples of malware.
 Other malware programs include;
Computer Worm: This is a program that uses computer network to spread itself.
 Trojan Horses: This is illegal instructions placed in the middle of a legitimate program.It is hidden program that runs on your computer without your knowledge.
Logic Bombs: This type of malware do not replicate, they are designed to destroy data on the computer system once certain conditions have been met.
Spyware: It is written to spy through a legal software.it changes computer’s configuration and personal information.

VIRUS DETECTION SOFTWARE (ANTI-VIRUS) This is a program written by the programmer to get rid of computer viruses. Some anti-virus are programmed to kill the virus and the effect done to the computer while others prevent the virus from entering the computer system. Anti-virus software is computer software used to prevent, detect and remove malicious software. Examples are; karpersky,E-scan,Avast,McAfee, etc

The Art of Information Processing

INFORMATION PROCESSING  
 THE ART OF INFORMATION PROCESSING INTRODUCTION
Information is data that has been processed in such a way that it is meaningful to the person who receives it. Information is also referring to facts and opinions provided and received during the course of daily life. Information processing is the change of information in any manner detectable by any observer. As such it is a process that describes everything that happens (changes) in the universe from the falling of a rock to the printing of a text file from a digital computer system.
 DEFINITION
Information processing is the process of acquiring, obtaining, recording, organizing, Storing and dissemination of information. OR Information processing refers to the manipulation of digitalized information by computers and other digital electronic equipment.
 PROCEDURES FOR INFORMATION PROCESSING 
The procedures for information processing can be categorized into; 1.Collation of information 2.Organisation of information 3.Analysis of information 4.Interpretation of information
1. COLLATION OF INFORMATION: Collation is the assembly of written information into a standard order. Many systems of collation are based on numerical order or alphabetical order. Collation is a fundamental element of most office filling systems, library catalogs and reference books Benefits of collation i. It makes it faster and easy for a user to find an element in the list or to confirm that it is absent from the list. ii. Search operation can be done automatically using the binary search or manual searching. iii.The first and last element can be easily found in a given range.

2.ORGANIZATION OF INFORMATION: Organizing skills helps in arranging information in such a way that it can be used more effectively. This essentially involves the following: 1.Comparing and contrasting 2.Classifying perceptions 3.Ordering perceptions/events 4. Representing ideas/perceptions The nine basic ways of organizing information are: 1.Alphabet 6. Hierarchy 2.Category 7. Chronological 3.Continuum 8. Geographical 4.Location 9.Value Size 5.Time

3.ANALYSIS OF INFORMATION: Since information is the raw material of decision making, it is crucial to learn how to analyze it. Analysis part may be adding up numbers and averaging them or comparing information to examine the relationship of one thing to another or two things together. Two ways to analyze information are; a.) Tally sheets b.) Summary sheets

 4. INTERPRETATION OF INFORMATION: During the interpretation stage, searcher’s assess the usefulness of their information and reflect to develop personal meaning. Information requires interpretation to become knowledge. Interpretation of information involves the following 1) Inferring 2)Drawing conclusions 3)Filtering information (point of view bias etc.) 4) Comparing and contrasting 5) Determining credibility 6) Classifying 7) Evaluating information 8) Evaluating information to support or result a problem or research question...
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Types of Binary code schemes

BINARY CODING SCHEMES Binary coding scheme is a method used for representing all of the digits’ letters, special characters and symbols using the binary digits Os and 1s.

 Three types of binary coding schemes are;
1)ASCII: Stands for American Standard Code for Information Interchange. This is the most widely used binary code for microcomputers

.2) EBCDIC: Stands for Extended Binary Coded Decimal Interchange Code.it was developed by IBM and is used for primarily for large computers.\

3) Unicode: it is 16-bits code design to support international languages such as Chinese and Japanese. it was developed by Unicode Inc. with support from Apple, IBM and Microsoft.

syllabus for data processing exam.

click on the link for tabular explanation....
http://www.pmbgs-abeokuta.org.ng/download/ebooks/DATA%20PROCESSING.pdf




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OBJECTIVES OF THE SYLLABUS The objectives of the syllabus are to test candidates’ (i) acquisition of basic skills of data processing and management; (ii) level of competence in ICT applications that will promote the acquisition of entrepreneurial skills for everyday living in the global world; (iii) knowledge in the application of ICT in facilitating business transaction and education; (iv) preparedness for further studies in Data Processing and Management. EXAMINATION SCHEME There will be two papers, Papers 1 and 2 both of which shall be taken as a composite paper at one sitting. PAPER 1: will consist of forty multiple-choice objective questions, all of which are to be answered in 1 hour for 40 marks. PAPER 2: will consist of two sections: Sections A and B. Candidates will be required to answer five questions in all. Section A: will consist of four essay questions. Candidates will be required to answer any three in 1 hour for 30 marks. Section B: will be a test of practical work. It shall consist of two compulsory essay questions to be answered in 1 hour for 40 marks.
DETAILED SYLLABUS S/N TOPICS CONTENT NOTES 1 INFORMATION AGE History of Computers i. Computing devices. ii. Concept of Number system in computing. iii. Generations of Computer: first, second, third, fourth, fifth generations of computer. Candidates should identify the various computing devices since the beginning of counting/computing. Should include the importance of number system to computing. Relate each generation with its characteristic feature. describe each generation under the following: year of development, basic component/type of technology, speed of operation, storage capacity/component. 2 Data and Information i. Definition of data and information. ii. Types of Data. ii. Ways of handling Data. iii. Definition of Data. iv. Digitalization. Differences between data and information should be emphasized 3 BASIC COMPUTING Classification of Computers Classify computers by: Type, Size, Usage. 4 Application of ICT in everyday life i. Uses of ICT in everyday activities. ii. Impact of ICT in the society. The use and areas of ICT application should be linked to societal development. 5 Components of i. Input Devices. Examples of each component Computers ii. Output Devices. iii. System Unit. iv. Storage Devices should be treated and how they are used in data processing. 6 INFORMATION PROCESSING The art of Information processing i. Definition of Information Processing. ii. Steps involved in Information Processing. Description of each step involved in information processing is required. 7 INFORMATION TRANSMISSION Process of Information transmission i. Definition of information transmission. ii. Methods of transmitting information. Modes of information transmission such as visuals(newspaper), audio(radio, telephone), audiovisual(GSM, Television) are required. 8 Medium of Information Transmission i. Types of Information Transmission. ii. Classification of means of transmission. Medium of information transmission such as radio, television, newspaper etc. 9 Networking i. Meaning of Networking, Internet and Intranet. ii. Types of Networking. Significance of networking should be mentioned Types such as MAN, LAN, WAN should be treated. 10 Internet i. Definition of Internet. ii. Benefits of internet iii. Internet browsers iv. Internet security v. Abuse of the Internet Candidates should be able to develop skills in the use of various services available on the internet 11 TOOLS FOR PROCESSING INFORMATION Operating System i. Definition of Operating System. ii. Types of Operating System. iii. Examples of Operating System. Differences between text iv. Functions of Operating System. (character) base interface and Graphical User Interface should be treated. 12 Word Processing i. Definition of Word Processing. ii. Uses of Word Processing iii. Examples of word Processing software. iv. Starting, loading and exiting word processing v. Creating, saving and retrieving documents Candidates should be able to make use of word processor to create and manipulate documents 13 Spreadsheet i. Definition. ii. Uses. iii. Examples of Spreadsheet Applications. iv. Loading and exiting spreadsheets. v. Creating, saving and retrieving Spreadsheet files. Candidates should be able to make use of spreadsheet to create and manipulate worksheets 14 Database Management System i. Definition. ii. Uses. iii. Examples of Database Applications. iv. Loading and exiting DBMS. v. Creating, saving and retrieving database files. i. Candidates should be able to use DBMS to create and manipulate Database files. ii. Include examples of packages for database management such as Microsoft Access. 15 Presentation Package i. Definition, uses, examples. ii. Loading and exiting Presentation programs. iii. Creating, saving and retrieving presentation files. i. Candidates should be able to use presentation programs to create and manipulate slides. 16 Web Design Packages i. Definition. ii. Uses. iii. Components. iv. Examples. Designing of web pages not required. 17 Graphic Packages i. Definition. ii. Uses of Graphic software packages. iii. Examples of graphic packages. Focus should be placed on Corel Draw COMPUTER MAINTENANCE, 18 ETHICS AND HUMAN ISSUES Maintenance of Computer i. General Cleaning. ii. Battery Charging and replacement for portable systems and UPS. iii. DVD drive lens cleaning. iv. Details of Hardware maintenance. v. Details of Software maintenance. vi. Computer crash and data recovery. Candidates should take note of basic maintenance procedures. Students should be able to ensure data integrity and recover data after a crash 19 Computer Ethics i. Computer room management ethics. ii. Laboratory rules and regulations. Responsible ways of using and securing computers 20 Safety Measures i. The sitting arrangement. ii. Positioning of the monitor, keyboard, CPU, mouse and any other peripheral devices. iii. Illuminating the computer room. iv. Maintaining a dust free environment. v. Keep liquid away from the computer room. Importance of safety measures should be emphasized. 21 Career opportunities in Data Processing i. Professions in computer. ii. Qualities of a good data processing professional. iii. Computer professional bodies. Duties of each professional/professional bodies should be treated. 22 Computer Virus i. Definition. ii. Types/Examples. iii. Sources. iv. Signals of virus warning v. Virus prevention, detection and deletion. Destructive effects of virus infection on computers DATA MANAGEMENT 23 Relational Model i. Database and table creation using application packages. ii. Creating relationships between tables iii. Creation of forms, queries and report. Arranging data in tables and forms should be emphasized The concept of primary and foreign keys, entities, attributes and relationships should be emphasized. Query language should be limited to those available to the database application package (e.g. query by example , SQL). 24 File Organization i. Definition of File organization. ii. Types of File organization. Comparison between the various types of File Organization is required. 25 Database Security i. Concept of data security, access control and data encryption. ii. Role of a database administrator. Importance of securing data is required 26 Parallel and Distributed databases i. Basic concept of parallel and distributed database. ii. Storing data in a distributed database (DBM) Definitions of concepts is required Significance of storing data in a distributed database management system is also required. LIST OF FACILITIES AND MAJOR EQUIPMENT/MATERIALS REQUIRED The table below shows the minimum requirement for a class of fifty candidates. ITEM NO. EQUIPMENT QUANTITY REQUIRED 1 Pictures/Charts showing different computing devices and other relevant information such as computers in a network 5 2 Computer system with Graphical User Interface (GUI), internet ready system; 5 3 Standard software packages such as Open Office, Microsoft office etc.(Latest version is desirable) 1 4 Multimedia systems and applications such as projector, speakers 1 5 Graphic packages such as corel draw.