FBI: Ransomware Actors Continue to Gain Access through Third Parties and Legitimate System Tools

FBI Private Industry Notification
TLP:CLEAR
November 7, 2023

Summary

The Federal Bureau of Investigation (FBI) is releasing this Private Industry Notification to highlight ransomware initial access trends and encourage organizations to implement the recommendations in the “Mitigations” section to reduce the likelihood and impact of ransomware incidents.

Threat

As of July 2023, the FBI noted several trends emerging or continuing across the ransomware environment and is releasing this notification for industry awareness. New trends included ransomware actors exploiting vulnerabilities in vendor-controlled remote access to casino servers, and companies victimized through legitimate system management tools to elevate
network permissions.

The FBI continues to track reporting of third-party vendors and services as an attack vector for ransomware incidents. Between 2022 and 2023, the FBI noted ransomware attacks compromising casinos through third-party gaming vendors. The attacks frequently targeted small and tribal casinos, encrypting servers and the personally identifying information (PII) of employees and patrons.

As of June 2023, the Silent Ransom Group (SRG), also called Luna Moth, conducted callback-phishing data theft and extortion attacks by sending victims a phone number in a phishing attempt, usually relating to pending charges on the victims’ account. Once the victims called the provided phone number, malicious actors directed them to join a legitimate system management tool via a link provided in a follow-up email. The threat actors then used the management tools to install other legitimate system management tools that can be repurposed for malicious activity. The actors then compromised local files and the network shared drives, exfiltrated victim data, and extorted the companies.