I'd say it could be described as "malicious" to redirect a site's traffic to another site, especially an adult one. It's not "good, clean fun", that's for sure. It has consequences for people.
True points, I was more commenting on how the connection between an admission that 'the site was compromised, we're going to take some time to fix things' resulting in a definite conclusion that the attack was malicious worked.
How does this make sense?
There didn't seem to be any hard damage done to any part of the site, as the comments said it looked more like an injection attack, so what's malicious? Looks to be more of a prank than anything.