The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known Zeppelin ransomware IOCs and TTPs associated with ransomware variants identified through FBI investigations as recently as 21 June 2022.
The FBI and CISA encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents.
Zeppelin ransomware is a derivative of the Delphi-based Vega malware family and functions as a Ransomware as a Service (RaaS). From 2019 through at least June 2022, actors have used this malware to target a wide range of businesses and critical infrastructure organizations, including defense contractors, educational institutions, manufacturers, technology companies, and especially organizations in the healthcare and medical industries. Zeppelin actors have been known to request ransom payments in Bitcoin, with initial amounts ranging from several thousand dollars to over a million dollars.
Zeppelin actors gain access to victim networks via RDP exploitation [T1133], exploiting SonicWall firewall vulnerabilities [T1190], and phishing campaigns [T1566]. Prior to deploying Zeppelin ransomware, actors spend one to two weeks mapping or enumerating the victim network to identify data enclaves, including cloud storage and network backups [TA0007]. Zeppelin actors can deploy Zeppelin ransomware as a
.exe file or contained within a PowerShell loader. 
Prior to encryption, Zeppelin actors exfiltrate [TA0010] sensitive company data files to sell or publish in the event the victim refuses to pay the ransom. Once the ransomware is executed, a randomized nine-digit hexadecimal number is appended to each encrypted file as a file extension, e.g.,
file.txt.txt.C59-E0C-929 [T1486]. A note file with a ransom note is left on compromised systems, frequently on the desktop.