This is realistic; there are examples you can see. Have a google around for Stuxnet; a fairly advanced piece of malware which went after Iranian nuclear enrich

This is realistic; there are examples you can see. Have a google around for Stuxnet; a fairly advanced piece of malware which went after Iranian nuclear enrichment centrifuges. It used five previously unreported Microsoft vulnerabilities and a bunch of fairly advanced techniques including jumping airgaps like ProjectSauron does via USB. There are samples of Stuxnet kicking about, if you want to take a look yourself there's nothing stopping you. Although, you may be there a while.