What would be the financial advantage for a malware designer to create lots of different malicious code instances that all exploit the same vulnerability yet have different malware signatures?

What will be an ideal response?

By creating lots of different instances of malware, a designer can sell each one as
a separate product. By having a different malware signature for each one he can guarantee
to his customers that the malware he is selling them will not have a signature that has
already been seen by the anti-malware companies.
Creativity