MOSCOW — A new wave of powerful cyberattacks hit Europe and beyond on Tuesday in a possible reprise of a widespread ransomware assault in May . Affected were a Russian oil giant , a Danish shipping and energy conglomerate , and Ukrainian government ministries , which were brought to a standstill in a wave of r ansom demands. Attack.Ransom The virus even downed systems at the site of the former Chernobyl nuclear power plant , forcing scientists to monitor radiation levels manually . Cyberattacks also spread as far as India and the United States , where the pharmaceutical giant Merck reported on Twitter that “ our company ’ s computer network was compromised today as part of global hack. ” The New Jersey-based company said it was investigating the attack . Cyber researchers say that the virus , which was linked to malware called Petrwrap or Petya , used an “ exploit ” developed by the National Security Agency that was later l eaked Attack.Databreach onto the Internet by hackers . It is the second massive attack in the past two months to turn powerful U.S. exploits against the IT infrastructure that supports national governments and corporations . The onslaught of r ansomware attacks Attack.Ransom may be the “ new normal , ” said Mark Graff , the chief executive of Tellagraff , a cybersecurity company . “ The emergence of Petya and WannaCry really points out the need for a response plan and a policy on what companies are going to do about ransomware , ” he said . T he attack Attack.Ransom mainly targeted Eastern Europe but also h it Attack.Ransom companies in Spain , Denmark , Norway and Britain . Victims included the British advertising and marketing multinational WPP and a shipping company , APM Terminals , based at the port of Rotterdam . But the damage was worst in Ukraine . Researchers at Kaspersky Lab ’ s Global Research and Analysis Team , in Russia , estimated that 60 percent of infected computers were in Ukraine and 30 percent in Russia . The hacks targeted government ministries , banks , utilities and other important infrastructure and companies nationwide , d emanding ransoms Attack.Ransom from government employees in the cryptocurrency bitcoin . The hacks ’ scale and the use of ransomware recalled the massive cyberattack in May in which hackers possibly linked to North Korea disabled computers in more than 150 nations using a flaw that was once incorporated into the National Security Agency ’ s surveillance tool kit . Cyber researchers have tied the vulnerability exploited by Petya to the one used by WannaCry — a weakness d iscovered Vulnerability-related.DiscoverVulnerability by the NSA years ago that the agency turned into a hacking tool dubbed EternalBlue . Petya , like WannaCry , is a worm that spreads quickly to vulnerable systems , said Bill Wright , senior policy counsel for Symantec , the world ’ s largest cyber­security firm . But that makes it difficult to control — or to aim at anyone in particular , he said . “ Once you unleash something that propagates in this manner , it ’ s impossible to control , ” he said . Although Microsoft in March m ade available Vulnerability-related.PatchVulnerability a patch for the Windows flaw that EternalBlue exploited , Petya uses other techniques to infect systems , said Jeff Greene , Symantec government affairs director .