Description

The Cuba ransomware gang was discovered using a mix of old and new approaches in assaults on critical infrastructure organisations in the United States and Latin American IT firms. In early June 2023, BlackBerry's Threat Research and Intelligence team discovered the new campaign, revealing that Cuba is now exploiting CVE-2023-27532 to steal credentials from configuration files. The vulnerability tracked as CVE-2023-27532  impacts products from Veeam Backup & Replication, with an exploit having been available since March 2023. Notably, a prior report from WithSecure had highlighted the active exploitation of CVE-2023-27532 by FIN7, a group linked to various ransomware operations. According to BlackBerry, Cuba's initial point of entry uses compromised admin credentials obtained via RDP access, rather than brute force methods.Next, Cuba has its own bespoke downloader known as 'BugHatch,' which communicates with its command and control (C2) server where downloader is in charge of retrieving DLL files and running commands. A Metasploit DNS stager is used by the group to get an early access  in the targeted environment and  stager directly decrypts and executes shellcode in memory. Additionally, Cuba employs the widely utilised BYOVD technique to disable endpoint protection measures and  also employ the BurntCigar program to kill kernel processes linked with security products. Cuba ransomware gang also leverages CVE-2020-1472, a weakness in Microsoft's NetLogon protocol, which gives the group with privilege escalation capabilities against Active Directory (AD) domain controllers. Furthermore, during the post-exploitation phase, Cuba was seen deploying Cobalt Strike beacons as well as different living-off-the-land binaries (lolbins). BlackBerry believes the gang is Russian in origin and has a financial purpose, as indicated by the exclusion of machines with Russian keyboard layouts from infections, the presence of Russian 404 pages in their infrastructure, language signs, and the group's focus on Western targets.