Ransomware Hits Hundreds of US Companies, Security Firm Says

A ransomware attack paralyzed the networks of at least 200 U.S. companies on Friday, according to a cybersecurity researcher whose company was responding to the incident. 

The REvil gang, a major Russian-speaking ransomware syndicate, appears to be behind the attack, said John Hammond of the security firm Huntress Labs. He said the criminals targeted a software supplier called Kaseya, using its network management package as a conduit to spread the ransomware through cloud service providers. Other researchers agreed with Hammond's assessment.  "Kaseya handles large enterprise all the way to small businesses globally, so ultimately, [this] has the potential to spread to any size or scale business," Hammond said in a direct message on Twitter. "This is a colossal and devastating supply chain attack." Such cyberattacks typically infiltrate widely used software and spread malware as it updates automatically.  It was not immediately clear how many Kaseya customers might be affected or who they might be. Kaseya urged customers in a statement on its website to immediately shut down servers running the affected software. It said the attack was limited to a "small number" of its customers.