A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the .. Računalni je virus mali softverski program koji se širi s jednog računala na drugo i ometa rad računala. Računalni virus može oštetiti ili izbrisati. Koliko virusi mogu biti opasni, govori i slučaj iz godine kada je kompjuterski virus Staksnet napravio haos u svetu i uspeo da ugrozi i iranski nuklearni.
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Some viruses employ polymorphic code in a way that constrains the mutation rate of the virus significantly. For example, an executable may be created and named “picture. It can be destructive such as deleting files on disk, crashing the system, or corrupting files or relatively harmless such as popping up humorous or political messages on screen.
Backups on removable media must be carefully inspected before restoration. The first one to appear on the Commodore Amiga was a boot sector virus called SCA viruswhich was detected in November Archived from the original on 29 June The virus program has managed to access the target user’s computer or software, but during this stage, the virus does not take any action.
Retrieved June 10, While virus infected files may be accidentally sent as email attachmentsemail viruses are aware of email system functions.
These are called cavity viruses. Polymorphic code was the first technique that posed a serious threat to virus scanners.
Archived from the original on 8 August Retrieved from ” https: Security software can then be used to check the dormant operating system files. Traditional computer viruses emerged in the s, driven by the spread of personal computers and the resultant increase in bulletin board system BBSmodem use, and software sharing. Antivirus software also needs to be regularly updated in order to recognize the latest threats. That is, each infected file contains a different variant of the virus.
Until floppy disks fell out of use, this was the most successful infection strategy and boot sector viruses were the most common in the “wild” for many years.
A virus may also send a web address link as an instant message to all the contacts e. One method of evading signature detection is to use simple encryption to encipher encode the body of the virus, leaving only the encryption module and a static cryptographic key in cleartext which does not change from one infection to the next.
The triggering phase can be caused by a variety of system events, including a count of the number of times that this copy of the virus has made copies of itself. Pritisnite OK da biste nastavili ili Cancel da biste ostali na trenutnoj stranici.
Virus Test Center, University of Hamburg. Archived from the original on 20 December Archived from the original on September 7, The virus places a copy of itself into other programs or into certain system kompjutrrski on the disk.
Different antivirus programs will employ different search strings, and indeed different search methods, when identifying viruses. Microsoft’s System File Kompmuterski improved in Windows 7 and later can be used to check for, and repair, corrupted system files. Likewise, an operating system on a kompuuterski CD can be used to start the computer if the installed operating systems become unusable. Ransomware is a virus that posts a message on the user’s screen saying that the screen or system will remain locked or unusable until a ransom payment is made.
Archived from the original on July 4, American Eagle Publications, Inc. Antivirus software does not change the underlying capability of hosts to transmit viruses.
Archived from the original on 24 May Many Windows users are running the same set of applications, enabling viruses to rapidly kompjutersii among Microsoft Windows systems by targeting the same exploits on large numbers of hosts. And there’s a clear pattern here which suggests an analogy to an infectious disease process, spreading from one resort area to the next. Many such viruses can be removed by rebooting the computer, entering Windows ” safe mode ” with networking, and then using system tools or Microsoft Safety Scanner.
Other commonly used preventative measures include timely operating vurusi updates, software updates, careful Internet browsing avoiding shady websitesand installation of only trusted software.
Sprječavanje i uklanjanje virusa i drugog zlonamjernog softvera
The program with a personality. Shareware and bootleg software were equally common vectors for viruses on BBSs. Virus signatures are just strings of code that are used to identify individual viruses; for each virus, the antivirus designer tries to choose a unique signature string that will not be found in a legitimate program.
The original hard drive can then be reformatted and the OS and all programs installed from original media. This way, if data is lost through a virus, one can start again using the backup which will hopefully be recent.
Computer virus – Wikipedia
Retrieved June 21, Essays on Cellular Automata. This is one of the reasons that it is dangerous to open unexpected or suspicious attachments in e-mails. In the early days of the personal computermany users regularly exchanged information and programs on floppies.
The “payload” is the actual body or data that perform the actual malicious purpose of the virus.