Some of you may be aware of this, some of you may not, but there has been a recent phishing scam in the actual client of LoL.
Random accounts that are on your friends list probably at some point may have clicked the link, unaware of what it actually did, and are now randomly sending those links out to other people on their friends list. The result is an endless chain of people being sent the link that is now being spread even further through misinformation.
I will NOT post the link that is being used to phish, but I will inform any and all people I know to be aware of the situation. If you see ANY link in LoL, in client or otherwise and for that matter anywhere on the internet, that you do not know/have never been to before, DON'T CLICK ON IT.
Be mindful that this is happening at the moment. If you have friends who unfortunately didn't know the above 101 of link clicking and fell for the trap, advise them on how to remove it and help them in anyway you can. The best way to stop this is to avoid clicking the links, as it is a chain and if everyone is mindful of it now it will break.