Ryuk is a dangerous ransomware software that locks up Microsoft Windows systems and demands Bitcoin in exchange for decryption keys. Ryuk and the gang behind it have been attacking businesses, hospitals, and governments since 2018 and continue to pose a serious threat. After locking the computers or files, the attackers either leave a ransom note or send a follow-up email outlining the Bitcoin required to unlock the systems and files.
A few hundred thousand dollars may be requested as ransom by the Ryuk in most cases. Five months after Ryuk’s launch, in January 2019, the group behind it is thought to have made around 705.8 BTC from 52 transactions, amounting to $3,701,893.98 USD.