INDICATORS OF COMPROMISE

See Table 7 for IOCs obtained from FBI investigations.

See Tables 8–11 for IOCs obtained from trusted third-party reporting.

Disclaimer: The authoring organizations recommend network defenders investigate or vet IP addresses prior to taking action, such as blocking, as many cyber actors are known to change IP addresses, sometimes daily, and some IP addresses may host valid domains.

MITIGATIONS

The authoring organizations recommend all critical infrastructure organizations implement the mitigations below to improve your organization’s cybersecurity posture based on Black Basta’s activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

The authoring organizations also recommend network defenders of HPH Sector and other critical infrastructure organizations to reference CISA’s Mitigation Guide: Healthcare and Public Health (HPH) Sector and HHS’s HPH Cybersecurity Performance Goals, which provide best practices to combat pervasive cyber threats against organizations. Recommendations include the following:

• Asset Management and Security: Cybersecurity professionals should identify and understand all relationships or interdependencies, functionality of each asset, what it exposes, and what software is running to ensure critical data and systems are protected appropriately. HPH Sector organizations should ensure electronic PHI (ePHI) is protected and compliant with the Health Insurance Portability and Accountability Act (HIPAA). Organizations can complete asset inventories using active scans, passive processes, or a combination of both techniques.
• Email Security and Phishing Prevention: Organizations should install modern anti-malware software and automatically update signatures where possible. For additional guidance, see CISA’s Enhance Email and Web Security Guide.
  • Check for embedded or spoofed hyperlinks: Validate the URL of the link matches the text of the link itself. This can be achieved by hovering your cursor over the link to view the URL of the website to be accessed.
• Access Management: Phishing-resistant MFA completes the same process but removes ‘people’ from the equation to help thwart social engineering scams and targeted phishing attacks that may have been successful using traditional MFA. The two main forms of phishing-resistant MFA are FIDO/Web Authentication (WebAuthn) authentication and Public Key Infrastructure (PKI)-based authentication. Prioritize phishing-resistant MFA on accounts with the highest risk, such as privileged administrative accounts on key assets. For additional information on phishing-resistant MFA, see CISA’s Implementing Phishing-Resistant MFA Guide.
• Vulnerability Management and Assessment: Once vulnerabilities are identified across your environment, evaluate and prioritize to appropriately deal with the posed risks according to your organization’s risk strategy. To assist with prioritization, it is essential to:
  • Map your assets to business-critical functions. For vulnerability remediation, prioritize assets that are most critical for ongoing operations or which, if affected, could impact your organization’s business continuity, sensitive PII (or PHI) security, reputation, or financial position.
  • Use threat intelligence information. For remediation, prioritize vulnerabilities actively exploited by threat actors. To assist, leverage CISA’s KEV Catalog and other threat intelligence feeds.
  • Leverage prioritization methodologies, ratings, and scores. The Common Vulnerability Scoring System (CVSS) assesses the technical severity of vulnerabilities. The Exploit Prediction Scoring System (EPSS) measures the likelihood of exploitation and can help with deciding which vulnerabilities to prioritize. CISA’s Stakeholder-Specific Vulnerability Categorization (SSVC) methodology leverages decision trees to prioritize relevant vulnerabilities into four decisions, Track, Track*, Attend, and Act based on exploitation status, technical impact, mission prevalence, and impacts to safety and public-wellbeing.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, the authoring organizations recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The authoring organizations recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

1. Select an ATT&CK technique described in this advisory (see Tables 2-6).
2. Align your security technologies against the technique.
3. Test your technologies against the technique.
4. Analyze your detection and prevention technologies’ performance.
5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

The authoring organizations recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

REFERENCES

1. SentinelOne: Black Basta Ransomware | Attacks Deploy Custom EDR Evasion Tools Tied to FIN7 Threat Actor
2. Trend Micro: Ransomware Spotlight – Black Basta
3. Kroll: Black Basta – Technical Analysis
4. Who Is Black Basta? (blackberry.com)
5. Palo Alto Networks: Threat Assessment – Black Basta Ransomware

REPORTING

Your organization has no obligation to respond or provide information back to FBI in response to this joint CSA. If, after reviewing the information provided, your organization decides to provide information to FBI, reporting must be consistent with applicable state and federal laws.

FBI is interested in any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with threat actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file.

Additional details of interest include: a targeted company point of contact, status and scope of infection, estimated loss, operational impact, transaction IDs, date of infection, date detected, initial attack vector, and host- and network-based indicators.

FBI, CISA, and HHS do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, FBI and CISA urge you to promptly report ransomware incidents to FBI’s Internet Crime Complain Center (IC3), a local FBI Field Office, or CISA via the agency’s Incident Reporting System or its 24/7 Operations Center (report@cisa.gov or by calling 1-844-Say-CISA [1-844-729-2472]).

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, HHS, and MS-ISAC do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, HHS, and MS-ISAC.

VERSION HISTORY

May 10, 2024: Initial version.