Description

A new ransomware-as-a-service (RaaS) operation named Eldorado has emerged, targeting VMware ESXi and Windows systems. Active since March, the Eldorado gang has already claimed 16 victims, primarily in the U.S., across the real estate, educational, healthcare, and manufacturing sectors. Researchers from cybersecurity firm Group-IB have been tracking Eldorado's activities, noting the gang's promotion of their service on RAMP forums and their recruitment of skilled affiliates. Eldorado operates a data leak site to list its victims, although it was offline at the time of reporting. The ransomware, developed in Go, has distinct variants for Windows and Linux platforms, both utilizing the ChaCha20 algorithm for encryption. The malware generates unique keys and nonces for each file, which are then encrypted with RSA-OAEP. Encrypted files receive the ".00000001" extension, and ransom notes are placed in the Documents and Desktop folders. To maximize damage, Eldorado encrypts network shares via SMB and deletes shadow volume copies on compromised Windows systems. The ransomware avoids encrypting system-critical files and directories to keep systems functional, and it self-deletes by default to evade detection. Affiliates have customization options for their attacks, such as specifying directories to encrypt and targeting network shares, particularly on Windows systems. Group-IB's investigation indicates that Eldorado is a unique development, not derived from existing ransomware sources. The operation allows affiliates some level of customization, especially on Windows, marking it as a significant new threat in the cybersecurity landscape.