In a notice, the Federal Bureau of Investigation (FBI) said that the group is targeting enterprises in the financial, government, healthcare, manufacturing and information technology sectors.
"The FBI has identified, as of early November 2021, that Cuba ransomware actors have compromised at least 49 entities in five critical infrastructure sectors, including but not limited to the financial, government, healthcare, manufacturing and information technology sectors," the notice said on Friday.
Cuba ransomware is distributed through Hancitor malware, a loader known for dropping or executing stealers, such as Remote Access Trojans (RATs) and other types of ransomware, onto the victims' networks.
Hancitor malware actors use phishing emails, Microsoft Exchange vulnerabilities, compromised credentials, or legitimate Remote Desktop Protocol (RDP) tools to gain initial access to a victim's network.
Cuba ransomware actors have demanded at least $74 million and received at least $43.9 million in ransom payments.
The US has experienced the most reported incidents in the second quarter this year.
The second quarter of 2021 was a vibrant quarter for ransomware, earning its place as a high-profile cyber agenda item for the US administration following the Colonial Pipeline attack, according to the 'Advanced Threat Research Report: October 2021' by McAfee Enterprise.
Some of the most high-profile ransomware attacks of the year involved ransomware-as-a-service (RaaS), including the attack against Colonial Pipeline in the US by a 'DarkSide' affiliate.
Fuelled by cryptocurrencies, ransomware was involved in 79 per cent of the global cybersecurity incidents in the last 18 months of the pandemic, led by Conti and REvil ransomware attacks, another report from global cyber security firm Sophos showed last week.