Samas ransomware family uses Active Directory to perform reconnaissance and then infect entire networks, researchers said.
Samas uses publicly-available penetration testing tools for delivery, and its operators made $450,000 in ransom payments by this past December, said researchers at Javelin Networks.
Unlike most ransomware out there, which focuses mainly on encrypting local files, Samas spreads inside the entire network to encrypt files on every server and computer, the researchers said.
This operation occurs in three steps: The attackers steal domain credentials, identify targets via Active Directory reconnaissance, and then move laterally through the network, researchers said in a blog post.
Javelin Networks researchers, who compare the approach to a worm that usually spreads itself throughout the entire network, said the ransomware’s operators exploit a JBoss JMX-Console Authentication bypass in front-facing servers to gain access to the network.
Once inside the network, the attacker uses tools to extract and steal domain admin credentials and act as a legitimate user.
The next step involves the identification of targets to encrypt, an operation performed using by querying Active Directory, “because it stores all the corporation’s information. It’s a database that stores all users, endpoints, applications, and servers,” the researchers said. Using the CSVDE command-line Windows utility, the attacker can obtain the necessary information without risking exposure.
The attacker can then check active hosts using the PING command, and can install the malicious module on them using yet another Windows utility: PSEXEC. Because this is a legitimate, built-in command tool that IT managers use for remote control, the attack goes undetected.
Samas has mainly focused on organizations in the United States over the past year, but it also targets entities in Europe and Asia.