TOKYO - Japanese internet service provider GMO Internet Group Inc. said Tuesday it will offer a reward of up to $1 million for information leading to the identification of hackers involved in unauthorized access to its foreign exchange trading service.
The company said it will accept information in Japanese, English or Chinese under its "GMO Cybercrime Bounty" program from noon Wednesday until the perpetrators are arrested.
GMO also said it will pay up to 3 million yen ($19,000) to victims whose personal information is confirmed to have been exposed in the hack.
A hacker believed to be behind the unauthorized intrusion disclosed some customer information earlier Tuesday after threatening to do so, cybersecurity sources said.
A statement from the hacker claimed information linked to one GMO customer had been posted online after the company failed to respond to a $1 million ransom request, the sources said.
The information included the name, address and other personal information, though its authenticity was unclear.
The statement also warned that personal data of customers would be released daily. GMO has urged people not to view the information, saying that hackers could obtain access records and other data in the process.
GMO said late Monday that the hacker had threatened to disclose customer information and conduct a ransomware attack at noon. Prior to noon, GMO had called on users to back up data and unplug their computers.
From Monday, GMO began analyzing the devices of customers who have agreed to cooperate with its investigation. The move is intended to assess the extent of the unauthorized access, including whether malware has actually been installed.
The company will notify service users individually by email once countermeasures are identified.
The unauthorized access targeted the Onamae.com Desktop Cloud service. An investigation following a customer inquiry confirmed on Oct. 20 that an unauthorized program had been installed by a third party in the server environments of some customers.
GMO CEO Masatoshi Kumagai said Monday in a blog post that the hacker was demanding $50 million in cryptocurrency, which he said the firm will not pay.
In a press release issued the same day, the company reiterated that it will not comply with the attacker's demands, given that deletion of the information and prevention of its misuse cannot be guaranteed.
Finance Minister Satsuki Katayama, meanwhile, said that the government is urging financial institutions to take measures to defend against potential cyberattacks, noting that five foreign exchange trading firms using the GMO server service, such as OANDA Japan Inc., had been affected.
The companies, including Goldenway Japan Co. and Ava Trade Japan K.K., have reported to the Financial Services Agency that customers had been affected by the GMO cyberattack.
"We cannot rule out the possibility of further unauthorized transactions, so we will respond with a sense of urgency," said Katayama, who also serves as financial services minister.
