Search This Blog

Powered by Blogger.

Blog Archive

Labels

About Me

Showing posts with label cybercriminal group. Show all posts

FBI Warns of Silent Ransom Group Using Phishing and Vishing to Target U.S. Law Firms

 

The FBI has issued a warning about a sophisticated cybercriminal group known as the Silent Ransom Group (SRG), also referred to by aliases like Luna Moth, Chatty Spider, and UNC3753. This group has been actively targeting U.S.-based law firms and related organizations through advanced phishing techniques and social engineering scams. The group, which has been operational since 2022, is known for using deceptive communication methods to gain unauthorized access to corporate systems and extract sensitive legal data for ransom demands. In the past, SRG’s activities spanned across industries such as healthcare and insurance. 

However, since the spring of 2023, its focus has shifted to legal entities, likely because of the highly confidential nature of the data managed by law firms. The group commonly uses a method called callback phishing, also known as reverse vishing. In this approach, victims receive emails that appear to originate from reputable companies and warn them of small charges for fake subscriptions. The emails prompt users to call a phone number to cancel the subscription. During these calls, victims are instructed to download remote access software under the guise of resolving the issue. Once the software is installed, SRG gains control of the victim’s device, searches for valuable data, and uses it to demand ransom.  

In March 2025, SRG has adapted their strategy to include voice phishing or vishing. In this new approach, the attackers call employees directly, posing as internal IT staff. These fraudulent callers attempt to convince their targets to join remote access sessions, often under the pretext of performing necessary overnight maintenance. Once inside the system, the attackers move swiftly to locate and exfiltrate data using tools like WinSCP or a disguised version of Rclone. Notably, SRG does not prioritize escalating privileges, instead focusing on immediate data theft. The FBI noted that these voice phishing methods have already resulted in multiple successful breaches. 

SRG reportedly continues to apply pressure during ransom negotiations by making follow-up calls to victim organizations. While the group does maintain a public site for releasing stolen data, its use of this platform is inconsistent, and it does not always follow through on threats to leak information. A significant concern surrounding these attacks is the difficulty in detection. SRG uses legitimate system management and remote access tools, which are often overlooked by traditional antivirus software. The FBI advises organizations to remain vigilant, particularly if there are unexplained downloads of programs such as AnyDesk, Zoho Assist, or Splashtop, or if staff receive unexpected calls from alleged IT personnel. 

In response, the FBI urges companies to bolster cybersecurity training, establish clear protocols for authenticating internal IT requests, and enforce two-factor authentication across all employee accounts. Victims of SRG attacks are encouraged to share any information that might assist in ongoing investigations, including ransom communications, caller details, and cryptocurrency wallet data.

Cybercriminal Group UNC5537 Strikes with Major Data Breaches

 

In recent weeks, the cybercriminal group UNC5537 has made significant waves. This ransomware gang, potentially linked to ShinyHunters or Scattered Spider, stole over 560 million customer records from Ticketmaster. On May 28, they listed this data for sale on their revamped leak site, BreachForums, with a price tag of $500,000. Just two days later, the group claimed to have obtained 30 million account records from Santander Bank in Spain, demanding $2 million for the data. Both companies confirmed the breaches after these announcements.

A June 10 analysis by Mandiant, an incident-response firm now part of Google, revealed that these data leaks, along with at least 163 other breaches, were not due to system vulnerabilities but rather the exploitation of stolen credentials and inadequate multifactor authentication (MFA) controls. According to Mandiant, no evidence indicates that the breaches stemmed from Snowflake's enterprise environment. Instead, all incidents are traced back to compromised customer credentials.

While implementing MFA could have prevented the data theft from Snowflake's systems, the companies involved have broader issues beyond this single control. Businesses must ensure visibility into their attack surfaces, promptly disable accounts of former employees and contractors, and minimize entry points for attackers. Chris Morgan, senior cyber threat intelligence analyst at ReliaQuest, emphasizes that attackers often exploit basic security lapses. "Targeting the low-hanging fruit — in this case, insecure credentials — can be achieved with little effort from the threat actor but provides ample opportunities," he notes.

Key Lessons from Recent Cloud Breaches

1. Start With MFA and Then Go Beyond

There is significant room for improvement in MFA adoption. Despite reports showing that 64% of workers and 90% of administrators use MFA, over 60% of organizations still have at least one root user or administrator without MFA enabled. According to Ofer Maor, co-founder and CTO at Mitiga, achieving consistent and verifiable MFA implementation is crucial. He suggests that companies enforce and require MFA, disable non-SSO logins, and enhance security measures with device- or hardware-based authentication for sensitive infrastructure.

2. Use Access Control Lists to Limit Authorized IP Addresses

Organizations should implement access control lists (ACLs) to restrict user access to cloud services or at least review access logs daily for anomalies. Jake Williams, a faculty analyst at IANS Research, recommends restricting IP addresses for cloud infrastructure access and emphasizes the importance of access reviews to identify unexpected access points.

3. Maximize Visibility Into Cloud Services

Continuous monitoring of applications, log data, access activity, and data aggregation services is essential for detecting and preventing attacks. Organizations need to alert on specific behaviors or threats, which could have identified the cybercriminals' attempts to access cloud data, says Brian Soby, CTO and co-founder at AppOmni.

4. Don't Rely on Your Cloud Providers' Defaults

Cloud providers often prioritize usability over security, so relying solely on their default settings can be risky. For example, Snowflake's default settings do not require MFA, making it easier for attackers with compromised credentials to gain full access. Companies must go beyond these defaults and enforce higher security standards.

5. Check Your Third Parties

Even if a company does not directly use Snowflake or another cloud service, third-party providers might, exposing their data to risk. Ensuring that all service providers handling company data follow proper security measures is essential, as highlighted by IANS Research's Williams. Reaching out to service providers to confirm their security practices is crucial in protecting data in today's complex supply chain environment.