-
CBSE Important Questions›
-
CBSE Previous Year Question Papers›
- CBSE Previous Year Question Papers
- CBSE Previous Year Question Papers Class 12
- CBSE Previous Year Question Papers Class 10
-
CBSE Revision Notes›
-
CBSE Syllabus›
-
CBSE Extra Questions›
-
CBSE Sample Papers›
- CBSE Sample Papers
- CBSE Sample Question Papers For Class 5
- CBSE Sample Question Papers For Class 4
- CBSE Sample Question Papers For Class 3
- CBSE Sample Question Papers For Class 2
- CBSE Sample Question Papers For Class 1
- CBSE Sample Question Papers For Class 12
- CBSE Sample Question Papers For Class 11
- CBSE Sample Question Papers For Class 10
- CBSE Sample Question Papers For Class 9
- CBSE Sample Question Papers For Class 8
- CBSE Sample Question Papers For Class 7
- CBSE Sample Question Papers For Class 6
-
ISC & ICSE Syllabus›
-
ICSE Question Paper›
- ICSE Question Paper
- ISC Class 12 Question Paper
- ICSE Class 10 Question Paper
-
ICSE Sample Question Papers›
- ICSE Sample Question Papers
- ISC Sample Question Papers For Class 12
- ISC Sample Question Papers For Class 11
- ICSE Sample Question Papers For Class 10
- ICSE Sample Question Papers For Class 9
- ICSE Sample Question Papers For Class 8
- ICSE Sample Question Papers For Class 7
- ICSE Sample Question Papers For Class 6
-
ICSE Revision Notes›
- ICSE Revision Notes
- ICSE Class 9 Revision Notes
- ICSE Class 10 Revision Notes
-
ICSE Important Questions›
-
Maharashtra board›
-
Rajasthan-Board›
- Rajasthan-Board
-
Andhrapradesh Board›
- Andhrapradesh Board
- AP Board Sample Question Paper
- AP Board syllabus
- AP Board Previous Year Question Paper
-
Telangana Board›
-
Tamilnadu Board›
-
NCERT Solutions Class 12›
- NCERT Solutions Class 12
- NCERT Solutions Class 12 Economics
- NCERT Solutions Class 12 English
- NCERT Solutions Class 12 Hindi
- NCERT Solutions Class 12 Maths
- NCERT Solutions Class 12 Physics
- NCERT Solutions Class 12 Accountancy
- NCERT Solutions Class 12 Biology
- NCERT Solutions Class 12 Chemistry
- NCERT Solutions Class 12 Commerce
-
NCERT Solutions Class 10›
-
NCERT Solutions Class 11›
- NCERT Solutions Class 11
- NCERT Solutions Class 11 Statistics
- NCERT Solutions Class 11 Accountancy
- NCERT Solutions Class 11 Biology
- NCERT Solutions Class 11 Chemistry
- NCERT Solutions Class 11 Commerce
- NCERT Solutions Class 11 English
- NCERT Solutions Class 11 Hindi
- NCERT Solutions Class 11 Maths
- NCERT Solutions Class 11 Physics
-
NCERT Solutions Class 9›
-
NCERT Solutions Class 8›
-
NCERT Solutions Class 7›
-
NCERT Solutions Class 6›
-
NCERT Solutions Class 5›
- NCERT Solutions Class 5
- NCERT Solutions Class 5 EVS
- NCERT Solutions Class 5 English
- NCERT Solutions Class 5 Maths
-
NCERT Solutions Class 4›
-
NCERT Solutions Class 3›
-
NCERT Solutions Class 2›
- NCERT Solutions Class 2
- NCERT Solutions Class 2 Hindi
- NCERT Solutions Class 2 Maths
- NCERT Solutions Class 2 English
-
NCERT Solutions Class 1›
- NCERT Solutions Class 1
- NCERT Solutions Class 1 English
- NCERT Solutions Class 1 Hindi
- NCERT Solutions Class 1 Maths
-
JEE Main Question Papers›
-
JEE Main Syllabus›
- JEE Main Syllabus
- JEE Main Chemistry Syllabus
- JEE Main Maths Syllabus
- JEE Main Physics Syllabus
-
JEE Main Questions›
- JEE Main Questions
- JEE Main Maths Questions
- JEE Main Physics Questions
- JEE Main Chemistry Questions
-
JEE Main Mock Test›
- JEE Main Mock Test
-
JEE Main Revision Notes›
- JEE Main Revision Notes
-
JEE Main Sample Papers›
- JEE Main Sample Papers
-
JEE Advanced Question Papers›
-
JEE Advanced Syllabus›
- JEE Advanced Syllabus
-
JEE Advanced Mock Test›
- JEE Advanced Mock Test
-
JEE Advanced Questions›
- JEE Advanced Questions
- JEE Advanced Chemistry Questions
- JEE Advanced Maths Questions
- JEE Advanced Physics Questions
-
JEE Advanced Sample Papers›
- JEE Advanced Sample Papers
-
NEET Eligibility Criteria›
- NEET Eligibility Criteria
-
NEET Question Papers›
-
NEET Sample Papers›
- NEET Sample Papers
-
NEET Syllabus›
-
NEET Mock Test›
- NEET Mock Test
-
NCERT Books Class 9›
- NCERT Books Class 9
-
NCERT Books Class 8›
- NCERT Books Class 8
-
NCERT Books Class 7›
- NCERT Books Class 7
-
NCERT Books Class 6›
- NCERT Books Class 6
-
NCERT Books Class 5›
- NCERT Books Class 5
-
NCERT Books Class 4›
- NCERT Books Class 4
-
NCERT Books Class 3›
- NCERT Books Class 3
-
NCERT Books Class 2›
- NCERT Books Class 2
-
NCERT Books Class 1›
- NCERT Books Class 1
-
NCERT Books Class 12›
- NCERT Books Class 12
-
NCERT Books Class 11›
- NCERT Books Class 11
-
NCERT Books Class 10›
- NCERT Books Class 10
-
Chemistry Full Forms›
- Chemistry Full Forms
-
Biology Full Forms›
- Biology Full Forms
-
Physics Full Forms›
- Physics Full Forms
-
Educational Full Form›
- Educational Full Form
-
Examination Full Forms›
- Examination Full Forms
-
Algebra Formulas›
- Algebra Formulas
-
Chemistry Formulas›
- Chemistry Formulas
-
Geometry Formulas›
- Geometry Formulas
-
Math Formulas›
- Math Formulas
-
Physics Formulas›
- Physics Formulas
-
Trigonometry Formulas›
- Trigonometry Formulas
-
CUET Admit Card›
- CUET Admit Card
-
CUET Application Form›
- CUET Application Form
-
CUET Counselling›
- CUET Counselling
-
CUET Cutoff›
- CUET Cutoff
-
CUET Previous Year Question Papers›
- CUET Previous Year Question Papers
-
CUET Results›
- CUET Results
-
CUET Sample Papers›
- CUET Sample Papers
-
CUET Syllabus›
- CUET Syllabus
-
CUET Eligibility Criteria›
- CUET Eligibility Criteria
-
CUET Exam Centers›
- CUET Exam Centers
-
CUET Exam Dates›
- CUET Exam Dates
-
CUET Exam Pattern›
- CUET Exam Pattern
CBSE Class VII Computer Science Chapter 15 – The Virus
Virus is a program that is loaded onto a computer without the users knowledge. It self-replicates and infects a computer. A virus corrupts or deletes data on the computer and spreads itself to other computers. It may even erase everything on the hard disk. Malicious is any software that enters into a computer and damages it without the knowledge of the user.
Spyware is a type of malware that is installed on computers and collects information about users without their knowledge. Worm is a special type of virus that makes copies over and over and uses memory but cannot add itself to other programs. Trojan horse is a simple program that pretends to be a useful application while it always does something destructive. It is not self replicating.
A Trojan can spread only when it is copied to another system. A virus can be broadly classified into three categories: boot virus, program file virus and macro virus. Boot virus affects the boot sector of both hard disks and floppy disks. Program file viruses infect executable program files.
Macro virus affects macros in Word documents. A virus can cause problems in a computer in many ways such as: deleting or damaging files, frequent hanging of the system, etc. If the computer is behaving strange, it could be infected or have malware installed. Antivirus software is a computer program that detects, prevents and takes action to disarm or remove malicious software programs, such as viruses and worms.