Investigation Shows Ryuk Ransomware Attack Caused by Pirated Software, Lack of Network Protection

Investigation Shows Ryuk Ransomware Attack Caused by Pirated Software, Lack of Network Protection

Sophos recently revealed that a cyberattack involving Ryuk ransomware targeting a European biomolecular research institute was caused by a pirated software and lack of network protection.

According to Sophos, its Rapid Response team was called in to respond to a Ryuk ransomware attack targeting a European biomolecular research institute – an organization that partners with local universities and works with students on various programs.

The Ryuk ransomware attack on the European biomolecular research institute, Sophos reported, costs the institute a week’s worth of vital research data, as even though the institute had backups, these backups weren’t up to date. The operation of the institute was also impacted since all computer and server files were required to be rebuilt before the data could be restored.

Initial Compromise

A review of logs and historical data available traced the initial compromise of the Ryuk ransomware attack on the European biomolecular research institute to the moment when one of the institute’s partners, an external university student, installed a pirated data visualization software on the said student’s laptop.

The investigating team found that the institute allowed people outside the organization to access its network, with partners such as university students allowed to access the institute’s network via remote Citrix sessions without the need for two-factor authentication using their own personal computers.

The investigating team found that the partner-student of the institute who installed the pirated software posted a question on an online research forum asking if anyone knew of a free alternative of the data visualization software, of which an original software costs hundreds of dollars a year. When the partner-student of the institute didn’t find a free version, a pirated version was used instead.

According to Sophos’ Rapid Response team, the pirated software was a pure malicious software (malware) that immediately triggered a security alert from Windows Defender. In order to install the pirated software, the partner-student of the institute disabled Windows Defender as well disabled Windows Security Firewall.

The installed pirated software-malware capabilities include logging keystrokes, stealing browser, cookies and clipboard data. The pirated software-malware also enabled the attackers to steal the student’s access credentials for the institute’s network.

According to Sophos’ Rapid Response team, 13 days after the installation of the pirated software-malware, a remote desktop protocol (RDP) connection was registered on the institute’s network using the student’s credentials, and 10 days after this connection was made the Ryuk ransomware was launched. The investigating team added that the institute’s RDP connection triggers the automatic installation of a printer driver, enabling users to print documents remotely.

“It is unlikely that the operators behind the ‘pirated software’ malware are the same as the ones who launched the Ryuk attack,” said Peter Mackenzie, manager of Rapid Response at Sophos. “The underground market for previously compromised networks offering attackers easy initial access is thriving, so we believe that the malware operators sold their access on to another attacker. The RDP connection could have been the access brokers testing their access.”

Cybersecurity Best Practices

The Ryuk ransomware attack that targeted the European biomolecular research institute is a hard-earned lesson for the community.

While the partner-student of the institute is clearly at fault for using pirated software, the said cyberattack exposed the institute’s network weaknesses. Here are some of the cybersecurity best practices in order to fortify your organization’s network against cyberattacks such as Ryuk ransomware attack:

• Use two factor-authentication as this is an added layer of security
• Enable Windows Defender as well Windows Security Firewall
• Keep backups up to date
• Practice Network Segmentation
• In network segmentation, your organization’s network is divided into sub-networks so that in case one sub-network is compromised, the other sub-networks won’t be affected.
• Implement Least Privilege Access
• The least privilege concept restricts access to your organization’s network to only those who are required to perform routine, legitimate activities.
• Secure Remote Desktop Protocol (RDP) Connection

RDP is a proprietary protocol developed by Microsoft that allows users the ability to connect to another computer over the internet. In the blog post "Cybercriminals Actively Exploiting RDP to Target Remote Organizations", McAfee Labs said that as a result of the COVID-19 restrictions, organizations wanting to maintain operational continuity have allowed their employees to access networks remotely via RDP with minimal security checks in place, giving cyber attackers easy access to these networks.

In the past few years, a handful of RDP security vulnerabilities have been identified and patched by Microsoft. Organizations that lagged behind in applying these RDP patches are vulnerable to attacks.

In the blog post “Data science for cybersecurity: A probabilistic time series model for detecting RDP inbound brute force attacks,” Microsoft said that RDPs that are not protected by strong passwords, multi-factor authentication, virtual private networks (VPNs), and other security protections are vulnerable to brute force attack – a type of cyberattack that uses the trial-and-error method in guessing the correct username and password combination.