SamSam Ransomware campaign evolution continues and this time a new variant but there is no difference in the encryption mechanism when compared to old variants. With the new variant some string obfuscation and anti-analysis techniques added to make detection difficult.
The SamSam ransomware campaign targetting multiple industries including Government, Healthcare, ICS and also the individuals associated with Healthcare sector.
The new variant was observed by Talos in conjunction with Cisco IR Services.Researchers said ” The initial infection vector for these ongoing attacks is currently unknown. History of SamSam indicates that attackers may follow their previous modus operandi of exploiting a host and then laterally moving within their target environment to plant and later run the SamSam ransomware”.
The new ransomware variant is encrypted one and some anti-forensic methods, as like the previous variants the deployment of the ransomware is manual and the symmetric keys generated randomly based on each file.
Threat actors hardcoded the Tor onion service and the Bitcoin wallet address in the payload. As like any other ransomware SamSam variant also assure ‘we don’t want to damage our reliability’ and ‘we are honest’. Also, they advertise offer free decryption for two files.
SamSam Ransomware mechanism
With the new variant, attackers employ a new methodology called “runner” which can search for .stubbin extension in its execution directory, and this file contains the encrypted Samsam ransomware.
Researchers said The new version also obfuscates functions, class names and strings, including the list of targeted file extensions, the help file contents and environment variables, this time using DES encryption with a fixed hard-coded key and the IV.
What next: if you’re Infected
Disconnect the Network
Determine the Scope
Understand the version or Type of Ransomware
Determine the Strains of Ransomware
Fast Emergency Response