Palmer Construction Targeted by BianLian Ransomware Group

Palmer Construction has reportedly been compromised by the BianLian ransomware group. The attack allegedly exfiltrated 475 GB of data, including personal data, accounting records, budget details, financial data, contract data, NDAs, and employee profiles. Palmer Construction is a Pennsylvania-based commercial construction business. It offers a wide array of services, from pre-design through construction and delivery.

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 appeared 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 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 they are 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 abandoned the RaaS model in favor of pure data extortion attacks where data is exfiltrated and ransom demand issued, 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.