An overwriting virus ( overwriting infector) is a malicious program which, after infection, will effectively destroy the original program code, typically by overwriting data in the system’s memory (overwrites the host program).
Many consider overwriting viruses to be extremely harmful because they actually destroy elements of a user’s system.
What is malicious program and program code
Malicious Program:It is a computer programe,which are specifically designed to delete, block, modify, or copy data or to disrupt the performance of computers and/or computer networks. This class includes viruses, worms, Trojans, and other programs used to automatically conduct malicious activity (hacking tools, constructors which can be used to create polymorphic code etc.).
Program Code:Program Code, is “special” words that your computer can understand, saved as a “document” or file. All computer code is just a lot of these “special” words.
For example when you search for “computers in america”,it is converted into something like this in top bar “https://www.google.com/search?q=computers+in+america&oq=computers+in+america&aqs=chrome..69i57j0l7.9613j0j1&sourceid=chrome&ie=UTF-8”
This is what we mean as “specil” words and is program code.
An overwrite virus deletes user data – documents, pictures, videos etc in such a way that they cannot be recovered.It “writes over them” with random data.They can alter any file on the system disk or stored in memory.
An overwrite virus actually removes the data completey. No chance of recovery.It is not deleting of a file,which can be recovered.It simply destroys it.
The damage it can cause is two-fold:
1.By overwriting programs it renders applications un-operational because the original program is gone.
2.When it gets executed it’s payload can encrypt,steal data, etc.
The programs so destroyed,infected cannot easily be restored without full backups of applications and system files.