FROM LINEAR TO COMPLEX: AN UPGRADE IN RANSOMHOUSE ENCRYPTION

Summary from the TLDR InfoSec newsletter

Unit 42 analyzed the upgraded Mario encryptor used by the RansomHouse ransomware, which evolved from simple single-pass encryption to a two-factor scheme that uses both primary and secondary keys, with chunked file processing. The RaaS operation, tracked as Jolly Scorpius, specifically targets VMware ESXi infrastructure, using the MrAgent deployment tool to encrypt multiple virtual machines simultaneously. The enhanced encryption methodology, with non-linear file processing and dynamic chunk sizing, significantly complicates static analysis and decryption for defenders.