The U.S. Department of Homeland Security issued a warning Tuesday about a new ransomware attack that wreaked havoc on Russian media companies and Ukrainian transportation systems. The malware, dubbed Bad Rabbit, is disguised as an Adobe update but instantly locks up users’ computers and demands a ransom to restore access. Ukraine’s Odessa airport suffered flight delays as a result of the virus, and several Russian news agencies said they were affected. Bulgaria, Turkey, and Japan were also targeted, though no major outages were reported. The U.S. government did not report any victims in the U.S. but warned Americans not to pay any ransom and to immediately report any malware attacks to the FBI. The attack comes months after the WannaCry ransomware caused chaos around the world, shutting down hospitals, government institutions, and businesses for several days.