Early Local Reports
The hack was publicised just yesterday, assuring no technical information on its defence contracts or business partners have leaked. Though Mitsubishi didn’t claim anyone responsible yet, the local newspapers Nikkei and Asahi Shimbun, who first published this story made up analysis and resulted in Chinese cyber-espionage groups to be blamed. The alleged group as per them is Tick (a.k.a Bronze Butler) which had an active past of attacking Japanese firms. As per local media, the breach was realised when a suspicious file was discovered in their company servers, and when traced back, led to a compromised employee account! This minor access led them onto the entire network and accessing over tens of computers across all the departments and steal around 200MB sized business documents, as reported by Nikkei. Mitsubishi later admitted of data exfiltration.
The Public Statement
The hack was reported to happen in June last year, and Mitsubishi started investigating in September and announcing publicly just yesterday. In a statement it released, it said, According to another newspaper, Mitsubishi has reported this hack privately to its major customers being disclosing to the public as yesterday. Though common in other nations, a hack of such is considered to be a shameful incident in Japan, and Mitsubishi is assigned with many government projects as power grids, telecom, military equipment etc.