hacking attempt? i need answer on a question

so i just recieved a whisper from blizzardeu, and it said something like this: "Blizzardeu [GameMaster] hello, you are suspected for using third-party applications, please visit <snip> so we can review you account. if you dont do this your account will be stopped"
it said something like that. what tipped me off as a hacking attempt is the fact that it was a whisper, but i wanted to come in her to ensure myself. cause i dont wanna loose my account.
and for those wondering, no im not using any illegal third party apps. im usin LUI Ui and some addons from curse.com