Embargo Ransomware – Malware

Overview

Embargo ransomware is a newly emerged cyber threat that has rapidly gained attention in 2024 for its innovative use of Rust-based malware and its sophisticated operational model. Unlike traditional ransomware strains, Embargo operates under the ransomware-as-a-service (RaaS) model, enabling other cybercriminals to deploy its malware for a fee. This approach allows the group to scale its attacks more efficiently, while focusing on maximizing profits through both encryption and data exfiltration. Embargo is notorious for employing a double extortion tactic, where victims are not only forced to pay for the decryption of their files, but also to prevent the public release of their sensitive data. This combination of file encryption and data leaks has become a hallmark of modern ransomware, amplifying the pressure on victims to comply with the attackers’ demands.

What sets Embargo apart from other ransomware families is its use of Rust, a programming language known for its speed, security, and low memory usage. Rust’s characteristics make it an ideal choice for malware developers looking to create highly efficient and stealthy ransomware. Embargo’s executable leverages several advanced Rust libraries, enhancing its functionality and enabling it to carry out its malicious activities with precision. These libraries not only aid in the encryption of files but also assist in avoiding detection, making it harder for security systems to intercept the attack. The Rust-based design represents a shift in the ransomware landscape, with more cybercriminals opting for languages that offer better performance and resilience against traditional detection methods.

Targets

Information

How they operate

Infection and Execution Process

The initial infection of Embargo ransomware begins with a malicious executable file, which is written entirely in Rust. Upon execution, the ransomware’s command line options allow attackers to specify certain behaviors, such as logging encrypted files and setting up various execution parameters. Embargo utilizes several libraries and crates built in Rust to enhance its functionality and streamline its operation. For example, the Clap_builder crate is used to parse command-line arguments, while Log4rs handles output logging, recording every file successfully encrypted. This is crucial for attackers, as they can review the log file to ensure the malware has executed as expected.

The Humantime crate enables Embargo to parse and format time durations, a feature that may be employed to track the passage of time during the encryption process. Meanwhile, Ignore helps the ransomware automatically filter out specific files and directories based on predefined ignore globs, ensuring that critical system files or non-targeted data are not encrypted, which would alert security systems. Additionally, the Zeroize crate plays a vital role in securing the malware’s memory, securely clearing any sensitive data after use, thereby preventing detection through memory analysis techniques.

Data Exfiltration and Double Extortion

One of the defining features of Embargo is its use of a double extortion tactic. Before encrypting files, the ransomware exfiltrates sensitive data from the victim’s system. This exfiltration is designed to maximize the pressure on the victim, as the attackers threaten to release the stolen data unless the ransom is paid. The malware uses the Winapi-util crate to interact with the Windows operating system, gathering information such as the computer name and system details, which are then used to determine which files and data to steal.

Embargo then encrypts the victim’s files using the Chacha20 crate, which implements the ChaCha20 stream cipher. This encryption method is known for its speed and security, making it a preferred choice for modern ransomware groups. The ransomware appends random digits to the encrypted files, rendering them inaccessible without the decryption key. This encryption is typically coupled with the creation of a ransom note in every directory where files have been encrypted. The note provides instructions on how to contact the attackers and pay the ransom, further amplifying the pressure on the victim.

Ransom Note and Public Shaming

Upon completion of the encryption, Embargo’s ransomware note also includes a threat that the stolen data will be published on the group’s dark web blog if the ransom is not paid. The blog, accessible via the Tor network, serves as a platform to publicly shame victims who refuse to comply with the demands. Embargo’s use of the Tor network and the onion services ensures anonymity for the attackers while allowing them to expose the stolen data to a wide audience. This tactic significantly heightens the psychological pressure on victims, who may face reputational damage in addition to the financial and operational impact of the attack.

Conclusion

Embargo ransomware represents a new wave of cybercriminal activity, leveraging the performance and security benefits of Rust to create an efficient and stealthy ransomware strain. Its use of advanced libraries and techniques, such as command-line parsing, secure memory handling, and strong encryption, make it a formidable threat. The double extortion model and the added threat of public data exposure via the dark web further illustrate the growing sophistication of modern ransomware. As cybersecurity experts continue to develop defenses against such threats, the emergence of Embargo highlights the ongoing arms race between attackers and defenders in the fight to protect sensitive data and critical infrastructure.

References

• A Look Into Embargo Ransomware, Another Rust-based Ransomware