Photo: KIRILL KUDRYAVTSEV/AFP (Getty Images) It’s been a mystery as to who is responsible for the disastrous pummeling of Accellion, the global cloud provider that, in December, suffered through a large cyberattack. This week, researchers announced that the responsible party may have ties to two prominent hacker groups. Advertisement Accellion recently discovered that a threat actor had been exploiting zero-day vulnerabilities in its legacy file-transfer service application (called “FTA” for short)—a file-sharing and storage product used by approximately 300 clients. Despite subsequent patches, there has been a steady stream of FTA-related data breaches involving banks, universities, large companies, government agencies, and more.