Ryuk is a ransomware that encrypts a victim’s files and requests payment in Bitcoin cryptocurrency to release the keys used for encryption. It was discovered in August 2018 and is used exclusively in targeted ransomware attacks. The initial Ryuk infection vectors are tailored to the victim due to the targeted nature of its infections.
Often seen initial vectors are spear-phishing emails, exploitation of compromised credentials to remote access systems and the use of previous commodity malware infections. These attacks have caused a huge amount of loss towards any organizations that fall victim to their attack.