The following sentence is an example of which stylistic sentence pattern: “Within six hours, the computer virus had spread worldwide, infecting mail servers and Web servers and home users and business networks.”?
The sentence is an example of the stylistic sentence pattern called polysyndeton where a conjunction (such as and) is repeated in quick succession for dramatic effect.
The repeated use of and in this sentence could be avoided by just listing the servers and networks affected. In this case the author wanted to enhance the negative effect of the devastation due to the virus, so the reader would experience a greater impact from reading it.
There is more information here: