BianLian Data Extortion Group Targets ASA Holidays

The BianLian data extortion group has claimed an attack against Air Sino-Euro Associates (ASA Holidays). Although the company has published no official confirmation of the alleged cyberattack on ASA Holidays, the ransomware group has claimed to have extracted a huge amount of sensitive data, including finance-related data, human resource details, clients’ and partners’ business information, private personal data, internal and external correspondence, and SQL databases. ASA Holidays is one of Singapore's leading online travel agencies, offering group tours to various destinations around the world, including Europe, China, Japan, Korea, and Australia.

BianLian's Evolution

BianLian is not a traditional RaaS. They first emerged in June 2022 as a typical RaaS provider with Golang-based ransomware until a decrypter was released. In early 2023 they appear to have abandoned the ransomware payload portion of attacks in favor of less complicated data exfiltration and extortion attacks. This shows how successful the double extortion strategy is for ransomware groups, and we will likely see more groups join the likes of BianLian (and Karakurt before them).

Techniques and Targets

BianLian leverages open-source tooling and command-line scripts to engage in credential harvesting and data exfiltration. BianLian increased attack volumes as they have moved away from deploying ransomware payloads in favor of pure data extortion attacks, making them one of the more prominent groups in Q1-2023, although still lagging far behind leaders. It is unclear how much BianLian typically requests for a ransom amount, or if they are keen to negotiate the demand down.

BianLian successfully attacked several high-profile organizations before a free decryption tool was released to help victims recover files encrypted by ransomware. The group appears to have abandoned the RaaS model in favor of pure data extortion attacks where data is exfiltrated and ransom demand issues, but no ransomware is deployed. BianLian has been observed deploying a custom Go-based backdoor for remote access. BianLian uses PowerShell and Windows Command Shell to bypass and evade security solutions.

BianLian primarily targets financial institutions, healthcare, manufacturing, education, entertainment, and energy sectors by leveraging compromised Remote Desktop Protocol (RDP) credentials. Almost exclusively a data extortion attack group now, rarely observed deploying ransomware payloads.