Final answer:
A companion virus is specifically designed to take advantage of the extension search order of an operating system. It creates a file with the same name as an existing file but with a different file extension to trick the operating system into executing it.
Step-by-step explanation:
The type of virus that is specifically designed to take advantage of the extension search order of an operating system is Companion virus. A companion virus is a type of virus that creates a file with the same name as an existing file but with a different file extension. When the operating system searches for the file, it prioritizes the file with the new extension, allowing the virus to execute.
For example, if there is a file named 'document.docx' and the companion virus creates a file named 'document.exe', when the operating system searches for 'document', it will find and execute the 'document.exe' file instead of the original 'document.docx' file.