Computer virus is variety of the computer programs which’s distinctive feature is ability to reproduction (self-replication). In addition to it viruses can execute without the knowledge of the user other arbitrary actions, including harming to the user and/or the computer. For this reason viruses carry to harmful programs.
At the end of the 60-years in several «big» computers which were settling down at large research centers of the USA, very unusual programs were found. Unlike the programs which were obediently walking «on a chord», these programs did nothing, strongly decelerating computer operation, but spoiled nothing.
The first real viruses which capable of reproduction and have received own names were in the seventies registered: the big Univac 1107 computer «ached» with the virus Pervading IBM-360/37Q the virus Christmas tree built a nest.
The term «a computer virus» appeared in 1984 at conference on information security in the report of the employee of Lekhaysky University of the USA of F.Koen.
1. On November 2, 1988 the graduate of Kornelsky university Robert Tappan Morris launched the program which because of an error began uncontrolled distribution and repeated infection of nodes of a network on a network. About 6200 machines that made 7.3 % of a total number of machines on a network were as a result infected.
2. D.Cherv Morris was one of the first viruses, the counted losses though formally the worm didn't put any a damage to data in the infected computers, were evaluated on the amount of 98 253 260 dollars, and the world community seriously attended to a problem of computer viruses.
3. Species of viruses: «invisible beings», polymorphic, macro viruses. Classification of viruses:
1. on habitat (network, file, load)
2. on a method of infection of habitat (the resident – are in memory and are active before switching off or reset, non-resident – don't infect memory)
3. by destructive possibilities (harmless, harmless, dangerous, very dangerous)
4. on features of algorithm of a virus («partner-viruses», «viruses worms», «parasitic», «student's», «stealth viruses», «polymorph-viruses», «macro viruses»)
The anti-virus program (antivirus) is an initially program for detection and treatment of the programs infected with a computer virus, and also for preventing of infection of the file by a virus (for example, by means of vaccination).
Many modern antiviruses allow finding and deleting Trojan programs and other harmful programs. And on the contrary – the programs created as «firewalls», also find the functions which are making related them with antiviruses (for example, Outpost Firewall) that over time can lead to even more obvious distribution of sense of the term on security features generally. It is possible to recall also likeness of assignments of ADinf (positioned as an antivirus) and tripwire (IDS).
The first simplest anti-virus programs appeared almost right after appearance of viruses. Now the large companies are engaged in development of antiviruses. As well as at virus writers, in these sphere original receptions – but already for search and fight against viruses also were created. The modern anti-virus programs can find tens of thousands of viruses.
Unfortunately, the competition between the anti-virus companies led to that development goes towards increase in quantity of found viruses (first of all for advertizing), instead of towards improving of their detection (an ideal – 100 % detection) and algorithms of treatment of the infected files.
The antivirus software consists of computer programs which try to find, prevent reproduction and to delete computer viruses and other harmful programs.
Classification of antiviruses
Kaspersky, Evgeny Valentinovich used the following classification of antiviruses depending on their principle of action (defining functionality):
1. Scanners (out-of-date polyphagia’s option). Determine virus existence by a DB storing signatures (or their checksums) viruses. Their efficiency is defined by an urgency of virus basis and existence of the heuristic analyzer.
2. Auditors. Remember a status of file system that does further possible the analysis of changes. (A class the close to IDS).
3. Guarding (monitors). Trace potentially dangerous operations, giving out to the user the appropriate request for operation permission/prohibition.
4. Vaccines. Change the imparted file so that the virus against which the graft becomes, already read the file the infected. In the modern (2007) conditions when the quantity of possible viruses is measured by tens of thousands, this approach is inapplicable.
1. What is the computer graphics?
2. What tasks are considered by computer graphics?
3. What types of computer graphics exist?
4. What difference of these types?
5. Tell about color models
6. What is «permission»?
7. What treats video information output devices?
8. What is the Internet?
9. Tell about the main aspects the Internet
10. Tell about a coordinating organ the Internet
11. What makes theoretical bases the Internet?
12. What is the IP address?
13. What methods of separation of the IP address exist?
14. What is the network protocol?
15. How many levels the protocol of a network and for what they are intended contains?