Merck, a U.S.-based pharmaceutical giant, was among dozens of businesses affected by a sprawling cyberattack Tuesday 27th June.

Computer systems from Ukraine to the United States were struck and the victims facing demands to hand over a ransom or have their computer networks remain locked and inaccessible.

The cyber attack started as an attack on Ukrainian government and business computer systems ( an assault that appeared to have been intended to hit the day before a holiday marking the adoption in 1996 of Ukraine’s first Constitution after its break from the Soviet Union) and  from there spread around the world. 

Also pharmaceutical giant Merck, who has an office in Ukraine too,  has been affected by the so-called “Petya” cyber attack: “The company is currently experiencing a hostile ransomware attack on its network systems,” the internal communication said. “While IT risk management and global security respond to this threat please remain calm.”

Ransomware works by locking users out of their computers and demanding a ransom in order to re-gain entry. The ransom in his virus is reported to be $300 (£235).

The extent of the Merck hack is not yet known.

Read further: The Independent,  The Washington Post,