1) Most ISPs have something like this router/software -- one that is capable of injecting/redirecting web requests to whatever they want. I remember seeing this

1) Most ISPs have something like this router/software -- one that is capable of injecting/redirecting web requests to whatever they want. I remember seeing this kind of thing when I was a Comcast customer -- they implemented a bandwidth limit and to warn you that you were about to exceed it, they used this type of web request injection. 2) There's likely a profit motive here as the software that is being advertised via this injected message costs money. They're likely getting a commission/affiliate fee from every customer that installs said software via this notice.