TOR chat with Black Basta ransomware operator runs dry


The SonicWall Capture Labs threat research team has recently been tracking a ransomware family called Black Basta. Black Basta first appeared in April 2022 and is believed to be operated by a well organized cybercrime group called Fin7. It has been reported that this group has already breached over 90 organizations and caused over $1B USD in damage.


Infection Cycle:


Upon execution, a console appears with the following text:


It then quickly disables console output using the FreeConsole Windows API:


It obtains information about storage volumes attached to the system and begins its encryption process:


Encrypted files are given a “.basta” file extension.


The malware uses RSA encryption.  The key is hardcoded and can be seen in the decompiled binary:


Various configuration options can also be seen in the decompiled code:


In order to prevent system recovery, the malware disables volume shadow copies using the vssadmin.exe program:


The malware drops dlaksjdoiq.jpg


dlaksjdoiq.jpg contains the following image:


A ransom message is written to readme.txt.  This file is copied into all directories containing encrypted files:


readme.txt contains the following ransom message:


fkdjsadasd.ico is dropped onto the system:


It contains the following icon:


The tOr link leads to the following page:


After logging in using the requested information, a chat interface is presented:


We had the following conversation with the attacker but were unable to obtain information about file retrieval costs:


SonicWall Capture Labs provides protection against this threat via the following signature:

  • GAV: BlackBasta.RSM (Trojan)

This threat is also detected by SonicWall Capture ATP w/RTDMI and the Capture Client endpoint solutions.

Security News
The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.