VIRUS TECHNOLOGY. INTRODUCTION. The basics of computer Virus Summarizing what they are ? How they attack ? What we can do to protect our selves ?. What is Computer Virus ?.
Boot Sector Viruses
Hard Disk Master Boot Record (MBR)/ Partition Table Viruses
Floppy Disk Boot Sector Viruses
Direct Action Viruses
Batch File Virus
Fast Infector Virus
Slow Infector Viruses
Sparse Infector Viruses
The virus spreads to other systems
The propagated virus is activated
STAGE - 3
STAGE - 2
STAGE - 4
The created virus is released to the outside world
Users become aware of the virus and isolateit
STAGE - 1
The same or a diff. developer develops a diff. strain of a new virus and the progress begins afresh
Vaccine for the virus is developed
STAGE - 6
STAGE - 7
When the use of vaccine become widespread thevirus is eradicated
A virus must incorporate a replicating routine.
A virus should be able to install itself in the RAM.
A virus has a trademark trigger routine.
Some viruses have an encryption routine.
Most viruses are designed to exhibit some sort of stealth characteristics to avoid detection.
Enter by email,downloads,floppy disk or hacking
Then make copies of itself to spread.
They will wait for the signal for being activated.
Graphics and unusual text will appear.
Music will play for no reason.
Program and data file suddenly corrupted.
Disk volume is changed.
Files and directories have been changed suddenly.
Your computer goes slowdown.
System memory have been changed.
Hardware devices begin to exhibit unusual behavour.
Interrupt vector have been changed.
The larger amount of spreading the virus is user base, the more widespread and quicker the infection.
The level of piracy is also influence to spread.
The complexity & characteristics of the virus code helps a virus to spread effectively.
Internet is also cause to spread the virus quickly.
A virus is ‘bad’ or ‘good’ depends on the virus developer.
Virus is made of two parts.
Propagation mechanism Spreads comp. To comp.
It is a technical challenge that lets fun of designing it.
Propagated virus automatically spreading until halted.
Entire meaning is easy to get and hard to recover.
Ex. If a virus which acts as anti-virus that detect the
negative virus and remove from the system.
A love letter which is win32 based on e-mail
HOW DO I GET IT ?
Attachment named : LOVE-LETTER-FOR YOU.TXT
The warning is protect.vbs.
When it opened virus infects to the system.
Unless you are sure that the doc. Is free from virus.
If you are unsure than ask to the sender to confirm.
Difficult to open .mp2 , .mp3 , .midi , .wav Etc.
Difficult to open .jpg , .bmp , .gif etc
Anti-Virus is a specialized utility program which is used to detect , eradicate and prevent viruses.
It provides databases in notes.
It allows a program to be run natively.
Methodology of detecting, and incorporate anti-virus.
They have their own database to compare string of virus string to detect.
An intelligent virus may breakdown your anti-virus s\w.
Timely and regularly upgrade the anti-virus s\w
If more than one user use one computer ,always check all local drives after download any data.
Clever virus may infect the anti-virus s\w.
Parallel you might be use the another corporate anti-virus.
If one fails than the other might be detect.
The developer make an anti-virus s\w after confirmation.
Directly it remove to your system memory.
Example of virus which is same as cancer cells.
Two ways of virus detection.
Signature based like polymorphic virus.
Rule based like genetic in nature.
Cat and mouse game bet’n developer and writers.
Limited database virus strings.
old version can’t detect.
Directly not work on on-line services.
Restricted coverage area for an anti-virus s\w