Full Report
2025-03-18 • Trellix • Jambul Tologonov, John Fokker • elf.blackbasta, win.blackbasta Open article on Malpedia
Analysis Summary
This article focuses on the **Black Basta Ransomware** operation, specifically referencing chat leaks related to its activity. The summary below is based on standard knowledge associated with Black Basta, as the provided context is only a citation header.
# Tool/Technique: Black Basta Ransomware
## Overview
Black Basta (also known as Baka or Basta) is a Ransomware-as-a-Service (RaaS) operation that emerged in early 2022. It is known for using a double-extortion model, encrypting victim data and threatening to leak it on their dedicated leak site (DLS) if the ransom is not paid.
## Technical Details
- Type: Malware family (Ransomware)
- Platform: Primarily Windows, with variants or associated components potentially targeting Linux/VMware ESXi environments (common for modern RaaS operations). The provided link mentions `elf.blackbasta`, suggesting Linux/ESXi targets alongside Windows (`win.blackbasta`).
- Capabilities: File encryption, data exfiltration, communication via dedicated chat/portal.
- First Seen: Early 2022
## MITRE ATT&CK Mapping
*Note: Generic mappings for ransomware operations based on typical observed behavior.*
- **TA0040 - Impact**
- **T1486 - Data Encrypted for Impact**
- N/A
- **T1485 - Data Destruction** (If data is deleted post-exfiltration/encryption)
- N/A
- **TA0010 - Exfiltration**
- **T1041 - Exfiltration Over C2 Channel**
- N/A
## Functionality
### Core Capabilities
- Utilizing a proprietary encryptor for files.
- Employing double-extortion tactics (encryption + data leak threats).
- Communication with victims through managed chat services/portals, as suggested by the article context (Chat Leaks).
### Advanced Features
- Uses a hybrid encryption scheme, often incorporating ChaCha20 for file encryption and RSA for key wrapping.
- Known to exploit vulnerabilities and leverage stolen credentials for initial access and lateral movement before deploying the ransomware payload.
- Historically associated with an older ransomware strain, **Ragnar Locker**, suggesting potential code reuse or overlap in tooling/affiliates.
## Indicators of Compromise
*Note: Specific IoCs are generally not provided in high-level summaries. The following are placeholders typical for this type of tool.*
- File Hashes: [Specific hashes would require analysis of the referenced article]
- File Names: [Varies; often uses unique extensions or executable names associated with the deployment phase]
- Registry Keys: [N/A - Typically focuses on execution persistence/disabling security tools]
- Network Indicators: [C2 addresses and domains related to the DLS or communication would be defanged, e.g., hxxps://blackbasta-files[.]com]
- Behavioral Indicators: High volume of file write/rename operations, temporary disabling of Volume Shadow Copy Service (`vssadmin delete shadows /all /quiet`).
## Associated Threat Actors
- **Black Basta RaaS Affiliates:** A relatively new group of affiliates operating under the Black Basta brand.
- Historically linked or compared to operators associated with **Ragnar Locker**.
## Detection Methods
- Signature-based detection: Signatures targeting the specific Black Basta executable binaries (both Windows and ELF variants).
- Behavioral detection: Monitoring for mass file encryption activities, immediate termination of security processes, or attempts to delete backup files.
- YARA rules: Rules targeting unique strings or cryptographic constants within the ransomware binary.
## Mitigation Strategies
- **Backup and Recovery:** Maintain immutable, offline backups.
- **Patch Management:** Promptly patch known exploited vulnerabilities used for initial access (e.g., major VPNs, zero-day applications).
- **Network Segmentation:** Restrict lateral movement capabilities.
- **Endpoint Detection and Response (EDR):** Deploy EDR solutions configured to detect high-entropy file encryption patterns.
## Related Tools/Techniques
- Ragnar Locker (potential predecessor/influence)
- LockBit (Similar RaaS model and operational tempo)