Difference Between Viruses, worms and trojans...?
What is Virus:-A computer virus is a small malicious code, which is written to disturb the computer working procedure. Even users will not have a view of it. There are some symptoms it should follow:
- It calls itself for execution, or patches the code in other programs.
- It can replace other program files with virus files, it must replicate itself
Some virus codes are programmed to damage the other programs, format hard-drive or delete files but some viruses replicate themselves and create problem for user as a memory chock or fill all the drive with text, video files. These all symptoms create system crashes or data lose issue with user computers.
Types of Viruses:-
- File infector viruses
- Boot sector viruses
- Master boot record viruses
- Macro viruses
- Multipartite viruses
File Infector mostly infect executable files like .exe or those porgram files which run from hard-drive ,floppy drive or Ram.
Boot Sector Viruses infect the boot file of Floppy or Hard-disk. These viruses corrupt the boot files of hard-drive so that operating system can't boot up. These viruses are memory resident as coded. Mostly are coded in Dos.Examples of boot sector viruses are Form, Disk Killer, Michelangelo, and Stoned.
Master boot record viruses works same as boot sector viruses, Master boot record viruses save the copy of master boot at different location so that Operating system can't find the record for booting file of OS.Examples of master boot record infectors are NYB, AntiExe, and Unashamed.
Multipartite viruses infects both boot records and data files, even infected file are not recoverable. if this virus stay on hard-drive then all the data file or boot record will be infected ,even any one is cleaned. Will be reinfected.Examples are One_Half and Anthrax.
Macro viruses infects data files of word, excel, PowerPoint and access. It can also infect other files. These kinds of infected files can be repaired. If someone know Visual basic then he can make macro viruses in Microsoft office 97.Examples of macro viruses are W97M.Melissa, WM.NiceDay and W97M.Groov
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Worms:-Worms are like viruses but they never corrupt files or damage any kind of sectors of hard-disk. Worms actually get control over computer memory and get the other Hosts Address from memory, after it sends copy of file over network, as result worms creates huge amount of data transmission over network, due to this any network get chock or system get out of resources.
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