New Delhi, Aug 18 (ANI): Twitter accounts of premium cable channel HBO were hacked and taken over by the notorious OurMine hacking group and posted # HBOHacked messages and warnings about security. The hacking group took control of the main HBO Twitter account, as well as those for TV shows including, 'Game of Thrones' and 'Girls', posting its usual statement: "Hi, OurMine are here, we are just testing your security, HBO team please contact us to upgrade the security." The network confirmed that they recently experienced a cyber incident, which resulted in the compromise of proprietary information, reports E! Online. They also explained, "The infringement on our social media accounts was recognized and rectified quickly." Upon a quick glance of HBO's Twitter accounts, “Everything has returned back to business as usual". The messages from OurMine were removed within an hour of their appearance, with HBO seemingly taking back control of its accounts. A HBO spokesperson said the TV network was "investigating" the hack.