I did not see that twitter posts myself and i have not heard about that stuff before, but i saw such posts on coinmarketcap itself a few days ago. Coinmarketcap has a relatively new feature called "CrypTown" where everyone that has an account on coinmarketcap can make a comment to any project that is listed on coinmarketcap and indicate if he is bullish or bearish about that project and why. In that comment section i saw the official coinmarketcap account making also posts about that cmc-token presale that is happening right now and of course a link to the sale. So it seems that more than just one account of coinmarketcap was hacked. Would be interesting to know, how many people fell victim to that scam.