They lost the less popular Nano coin digital coin previously known as RaiBlocks - worth US $ 170 million.
BitGrail became the second virtual currency exchange to lose huge amounts of money this year. Before this, Coincheck, a Tokyo-based stock exchange, suffered losses of around US $ 400-534 million due to cyber attacks.
Through its official website, BitGrail announces that it has lost $ 170 million in fraudulent transactions and they have reported this to the authorities. They have also suspended the retrieval and deposit of virtual currency in order to verify further.
However, unlike Coincheck who promised to return the user's money back, the BitGrail founder Francesco Firano announced via Twitter that they were unlikely to return all the lost user money.
Meanwhile, the Nano team said that they had "no reason to believe that this happened because of the Nano protocol" and "the problem arose because of BitGrail software."