How were viruses created?
Viruses may have arisen from mobile genetic elements that gained the ability to move between cells.
They may be descendants of previously free-living organisms that adapted a parasitic replication strategy.
Perhaps viruses existed before, and led to the evolution of, cellular life..
What are the two main types of computer virus?
The Three Major Types of Computer VirusesMacro viruses – These are the largest of the three virus types. They use built-in programming scripts in such applications as Microsoft Excel and Microsoft Word to automate the tasks. … Boot record infectors – These viruses are known also as boot viruses or system viruses. … File infectors – These viruses target .
What are the main types of viruses?
Based on their host, viruses can be classified into three types, namely, animal viruses, plant viruses, and bacteriophages.
What are the 2 types of viral replication?
There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.
What are the top 5 computer viruses?
With all that in mind, we’ve put together our list of the top computer viruses.Conficker. First discovered in 2008, Conficker, which had many aliases, including Downup, Downadup, and Kido is a worm that targets Windows operating systems. … ILOVEYOU. … Morris Worm. … Mydoom. … Stuxnet. … CryptoLocker. … Sasser & Netsky. … Anna Kournikova.More items…•