Thursday, June 20, 2024

Free Decryptor Tool Released for the Black Basta Ransomware

A vulnerability in the encryption algorithm used by the Black Basta ransomware has led researchers to develop a free decryptor tool.

Active since April 2022, the Black Basta ransomware group employs a double extortion strategy, encrypting the vital servers and sensitive data of their victims and threatening to reveal the sensitive information on their public leak site.

Since the beginning of 2022, the criminal group has received at least $107 million in Bitcoin ransom payments. Over 329 victims have been affected by the ransomware gang, according to the experts.

A free decryptor has been offered by independent security research and consulting company SRLabs to assist victims of the Black Basta ransomware in getting their files back.

How Can the Files Be Recovered?

Researchers claim that if the plaintext of 64 encrypted bytes is known, data may be recovered. The size of a file determines whether it may be recovered entirely or partially. Files with less than 5000 bytes in size cannot be restored. 

Complete recovery is achievable for files ranging in size from 5000 bytes to 1GB. The first 5000 bytes of files larger than 1GB will be lost; however, the remaining bytes can be restored.

“The recovery hinges on knowing the plaintext of 64 encrypted bytes of the file. In other words, knowing 64 bytes is not sufficient in itself since the known plaintext bytes need to be in a location of the file that is subject to encryption based on the malware’s logic of determining which parts of the file to encrypt”, the researchers said.

It is possible to know 64 bytes of plaintext in the correct location for several file types, particularly virtual machine disk images.

Researchers developed various tools to aid in analyzing encrypted files and determining whether decryption is feasible.

The decrypt auto tool may recover files containing encrypted zero bytes. Manual review may be required depending on how often and to what extent the malware has encrypted the file.

Decrypting file with the tool
Decrypting file with the tool

Researchers say a magic byte sequence that is not included in the encrypted file is left by the malware at the end. The file only has zero bytes after the tool has finished running. Thus, the file has been successfully decrypted.

The file successfully decrypted
The file successfully decrypted

Depending on the file size, the first 5000 bytes are used correctly by the keystream. Stated otherwise, those bytes—aside from the initial 64—will be lost.

Researchers say, “Virtualized disk images, however, have a high chance of being recovered because the actual partitions and their file systems tend to start later.

So the ransomware destroyed the MBR or GPT partition table, but tools such as “testdisk” can often recover or re-generate those.”


Latest articles

1inch partners with Blockaid to enhance Web3 security through the 1inch Shield

1inch, a leading DeFi aggregator that provides advanced security solutions to users across the...

Hackers Exploit Progressive Web Apps to Steal Passwords

In a concerning development for cybersecurity, hackers are increasingly leveraging Progressive Web Apps (PWAs)...

INE Security: Optimizing Teams for AI and Cybersecurity

2024 is rapidly shaping up to be a defining year in generative AI. While...

Threat Actor Claims Breach of Jollibee Fast-Food Gaint

A threat actor has claimed responsibility for breaching the systems of Jollibee Foods Corporation,...

Threat Actors Claiming Breach of Accenture Employee Data

Threat actors have claimed responsibility for a significant data breach involving Accenture, one of...

Diamorphine Rootkit Exploiting Linux Systems In The Wild

Threat actors exploit Linux systems because they are prevalent in organizations that host servers,...

Amtrak Data Breach: Hackers Accessed User’s Email Address

Amtrak notified its customers regarding a significant security breach involving its Amtrak Guest Rewards...
Guru baran
Guru baran
Gurubaran is a co-founder of Cyber Security News and GBHackers On Security. He has 10+ years of experience as a Security Consultant, Editor, and Analyst in cybersecurity, technology, and communications.

Free Webinar

API Vulnerability Scanning

71% of the internet traffic comes from APIs so APIs have become soft targets for hackers.Securing APIs is a simple workflow provided you find API specific vulnerabilities and protect them.In the upcoming webinar, join Vivek Gopalan, VP of Products at Indusface as he takes you through the fundamentals of API vulnerability scanning..
Key takeaways include:

  • Scan API endpoints for OWASP API Top 10 vulnerabilities
  • Perform API penetration testing for business logic vulnerabilities
  • Prioritize the most critical vulnerabilities with AcuRisQ
  • Workflow automation for this entire process

Related Articles