Zeus virus

I was browsing on my iPhone yesterday and get a pop up from cox stating that one of the PCs on my network might be infected with the virus zeus. I immediately contacted cox to see if they can tell me what PC it is and they said its the one that got the notification. Can iOS devices be infected by malware? I later that night contacted tech support with the ticket number and the email I received earlier that day and they gave me the IP address. When I logged in to my netgear router to see which device the IP address matched to it turned out to be the network port which according to the tech support agent is the modem. We reset the modem and changed the SSID and password for the router. could the virus be on any of my PCs?

Thanks!