The Exbyte data exfiltration tool
https://www.bleepingcomputer.com/news/security/blackbyte-ransomware-uses-new-data-theft-tool-for-double-extortion/
A BlackByte ransomware affiliate is using a new custom data stealing tool called 'ExByte' to steal data from compromised Windows devices quickly.
Data exfiltration is believed to be one of the most important functions in double-extortion attacks, with BleepingComputer told that companies are more commonly paying ransom demands to prevent the leak of data than to receive a decryptor.