Brazilian Banks Targeted by New AllaKore RAT Variant Called AllaSenha
Summary: If it seems suspicious, it probably is. Users should always err on the side of caution when it comes to sending out personally identifiable information through messages and emails.
Since at least early May, Banking institutions in Brazil have been observed by French cybersecurity company HarfangLab being targeted by a new campaign that deploys a custom payload variant of the Windows-based AllaKore RAT called AllaSenha. The intricate infection chain involves Python scripts and a loader developed in a language called Delphi. The final stage of the attack chain employs the main payload AllaSenha RAT, which aims to steal credentials for Brazilian bank accounts leveraging Azure cloud to perform C2 communication. Targets of the campaign include banks such as Banco do Brasil, Bradesco, Banco Safra, Caixa Econômica Federal, Itaú Unibanco, Sicoob, and Sicredi. The initial access vector, though not definitively confirmed, points towards the use of malicious LNK files in phishing messages that masquerade as a PDF. The LNK file executes a Windows command shell when launched that utilizes tactics like decoy PDFS and legitimate services to provide the appearance of legitimacy to the phishing attempt. The attacker then executes a Python script named BPyCode to deploy and rotate malicious infrastructure. In addition to stealing online banking account credentials from web browsers, AllaSenha comes with the ability to display overlay windows in order to capture two-factor authentication codes and even trick a victim into scanning a QR code to approve a fraudulent transaction initiated by the attackers.
Security Officer Comments:
There is evidence to suggest that the threat actors behind the activity previously abused legitimate services like Autodesk A360 Drive and GitHub to host the payloads. The threat actor continues to utilize social engineering to trick the victim by opening a decoy pdf when the command shell executes. Further analysis of comments and code by HarfangLab revealed the source code of AllaSenha is associated with a Portuguese-speaking individual named bert1m.
Suggested Corrections:
Associated IOCs have been published in the Appendix of HarfangLab’s blog post and on their GitHub repository. YARA rules are also available in the blog post.
General Phishing Suggested Correctionss for Organizations:
Link(s):
https://thehackernews.com/2024/05/brazilian-banks-targeted-by-new.html
https://harfanglab.io/en/insidethelab/allasenha-allakore-variant-azure-c2-steal-banking-latin-america/