Cyber attacks by hackers earlier this year led to the theft of technical trade secrets from a German steel-making giant that sells submarines to Israel , Essen-based ThyssenKrupp AG said Thursday.“ThyssenKrupp has become the target of a massive cyber attack,” the corporation said.The cyber attacks were reportedly detected in April and traces of the breaches were traced back to February of this year.The company stated that it has not identified hacks into its marine systems unit, which manufactures the likes of military submarines and warships sold to Israel.ThyssenKrupp, one of the world’s largest steel makers, attributed the breaches to unnamed attackers located in southeast Asia engaged in what it said were “organized, highly professional hacker activities.”The German company did not specify which documents had been stolen, nor the extent of their losses.However, it was reported that cyber hackers had stolen engineering data and information from other divisions of the ThyssenKrupp.The company has filed a complaint with local police.Last week, Israeli media reported on an Iranian state-owned firm holding stake in the Germany conglomerate.Israel’s Defense Ministry later contradicted initial remarks denying any knowledge of Iranian involvement in the German giant.Following a “thorough examination,” the ministry acknowledged that it had been aware since 2004 of the Iran Foreign Investments Company’s involvement in ThyssenKrupp.The Iranian investments in Thyssen- Krupp began in the 1970s and were inherited by the Islamic regime when it took over Iran in the 1979 revolution, Yediot Aharonot reported.The revelation came amid scrutiny in Israel of other aspects of the Israeli Defense Ministry’s contract with ThyssenKrupp in 2011.Attorney-General Avichai Mandelblit has ordered the police to look into allegations that Prime Minister Benjamin Netanyahu’s personal lawyer, David Shimron, used his close relationship with the premier to push for purchasing several submarines from ThyssenKrupp, award the company a contract for naval vessels to defend Israel’s gas fields and allow it to build a shipyard in Israel.JTA contributed to this report.