A German steel factory suffered massive damage after hackers managed to access production networks , allowing them to tamper with the controls of a blast furnace , the government said in its annual IT security report . The report , published Wednesday by the Federal Office for Information Security ( BSI ) , revealed one of the rare instances in which a digital attack actually caused physical damage . The attack used spear phishing and sophisticated social engineering techniques to gain access to the factory 's office networks , from which access to production networks was gained . Spear phishing involves the use of email that appears to come from within an organization . After the system was compromised , individual components or even entire systems started to fail frequently . [ Also on ITworld : Low and no - cost ways to learn about IT security . Do n't miss a thing ! Sign up for ITworld 's daily newsletter . ] Due to these failures , one of the plant 's blast furnaces could not be shut down in a controlled manner , which resulted in " massive damage to plant , " the BSI said , describing the technical skills of the attacker as " very advanced . " The attack involved the compromise of a variety of different internal systems and industrial components , BSI said , noting that not only was there evidence of a strong knowledge of IT security but also extended know - how of the industrial control and production process . The hack sounds similar to attacks involving the Stuxnet worm . Considered the first known cyberweapon , Stuxnet is believed to have been created by the U.S. and Israel to attack Iran 's nuclear program . Discovered in 2010 , the worm has espionage and sabotage functionalities that were used to destroy up to 1,000 uranium enrichment centrifuges at a nuclear plant near the city of Natanz in Iran . ;