HBO

The same organization that broke into Game of Thrones also hacked the HBO "Giphy" platform.

However, more than only the GIPHY program access was compromised.

The passwords for all of HBO's social media accounts were included in a file that was attached to the email from Mr. Smith.

Although HBO has presumably changed all of its passwords by this point.

Source: https://www.databreaches.net/hbo-hackers-obtained-all-of-hbos-social-media-logins-and-giphy-credentials/

"id": "HBO143911122",
"linkid": "hbo",
"type": "Breach",
"date": "08/2017",
"severity": "100",
"impact": "5",
"explanation": "Attack threatening the organization’s existence"