NCCIC and FBI have issued a threat alert about a ransomware called SamSam. It encrypts network systems without requiring user authentication.
PUBLISH DATE: 04-December-2018
The SamSam actors targeted multiple industries in the United States and Internationally, launching network-wide attacks against organizations to secure huge amounts of ransom payments. Organizations that provide services are primary target as they’re likely to produce speedy ransom in order to have their systems decrypted and their services restored.
The actors exploit Windows servers to access victim’s network and infect all reachable hosts. Beginning in 2016, cyber actors used the JexBoss Exploit Kit to access vulnerable JBoss applications. It was also discovered that these cyber actors use Remote Desktop Protocol (RDP) to gain persistent access to victims’ networks. Usually, attackers use stolen login credentials or Brute Force attacks to access the network. Therefore, RDP intrusion detection becomes hard because the malware enters through an authenticated access point.
Once successful access to a target network is achieved, the SamSam threat actors elevate their privileges to administrator rights and deploy malware on the server. An executable file is then run without needing authentication from the user. The executables then encrypt target computers. Ransom notes are found on the encrypted computers with instructions that direct victims to contact through a Tor hidden service site.
Once the ransom is paid in bitcoins, victims receive links to download cryptographic keys to decrypt their network.
Analysts believe that these stolen RDP credentials were purchased from known darknet marketplaces prior to SamSam’s attack. Other suspicious activity unrelated to SamSam found on victim networks indicates that the credentials had been stolen and sold to multiple threat entities.
INDICATORS OF COMPROMISE
SamSam is a variety of ransomware based on the .NET framework. Four different variants of the ransomware have been retrieved. Following are the indicators of compromise that were submitted for analysis of each of the four variants of SamSam ransomware.
Analysis indicates that these files are ransomware.
These files are designed to encrypt a victim’s system files for a ransom payment.
DHS and FBI recommend that users and administrators consider using the following best practices to strengthen the security posture of their organization’s systems. Administrators should review configuration changes prior to implementation to avoid any inconvenience or damage.
If you think you’re the victim of a cyber-attack, immediately send an e-mail to firstname.lastname@example.org.