Hvad er en computervirus eller en computerorm?

En væsentlig forskel mellem computervira og orme er, at vira kræver et aktivt værtsprogram eller et allerede inficeret og aktivt operativsystem for at køre virus, skade og inficere andre filer eller dokumenter, mens orme er enkeltstående ondsindede programmer, der kan formere sig selv og spredes via computernetværk uden menneskelig hjælp.

Vira er typisk knyttet til en eksekverbar fil eller et Word-dokument. De spredes ofte via P2P-fildeling, inficerede websteder og download af vedhæftede filer i e-mails. Når en virus finder vej ind i dit system, vil den forblive i dvale, indtil den inficerede værtsfil eller værtsprogrammet aktiveres, hvilket gør virussen aktiv igen, så den kan replikere sig selv i dit system.

Orme behøver derimod ikke et værtsprogram for at kunne køre, selvreplikere og sprede sig. Når en orm har fundet vej ind i dit system, normalt via en netværksforbindelse eller en downloadet fil, kan den herefter lave flere kopier af sig selv og sprede sig via netværk eller internetforbindelsen og inficere enhver ikke-beskyttet computer og server på netværket. Da hver efterfølgende kopi af netværksormen også kan selvreplikere, kan smitten sprede sig meget hurtigt via internettet og computernetværk.

How Do Computer Viruses Spread?

The Viruses and Worms subclass of malicious software programs includes the following:

• Email-Worm
• IM-Worm
• IRC-Worm
• Net-Worm
• P2P-Worm
• Virus

• Computer Worms
  Most known computer worms are spread in one of the following ways:
  
  
  • Files sent as email attachments
  • Via a link to a web or FTP resource
  • Via a link sent in an ICQ or IRC message
  • Via P2P (peer-to-peer) file sharing networks
  • Some worms are spread as network packets. These directly penetrate the computer memory, and the worm code is then activated.
    
    

• Computer worms can exploit network configuration errors (for example, to copy themselves onto a fully accessible disk) or exploit loopholes in operating system and application security. Many worms will use more than one method in order to spread copies via networks.

• Viruses
  Viruses can be divided according to the method that they use to infect a computer:
  
  
  • File viruses
  • Boot sector viruses
  • Macro viruses
  • Script viruses
    
    

• Any program within this subclass of malware can also have additional Trojan functions.

How to protect yourself against Computer Viruses and Worms

It’s recommended that you install anti-malware software on all of your devices – including PCs, laptops, Macs and smartphones – and that your anti-malware solution receives regular updates, in order to protect against the latest threats. A good anti-malware software product – such as Kaspersky Anti-Virus – will detect and prevent virus and worm infections on your PC, while Kaspersky Internet Security for Android is an excellent choice for protecting Android smartphones. Kaspersky Lab has products that protect the following devices:

• Windows PCs
• Linux computers
• Apple Macs
• Smartphones
• Tablets