Rhysida Ransomware Targets Malaysian Financial Institution

The Rhysida ransomware group has allegedly attacked the Malaysian Industrial Development Finance (MIDF) organization. The gang posted a message with a countdown of just seven days and urged potential buyers to seize the opportunity to buy exclusive and sensitive data from the institution. MIDF Group is a wholly-owned subsidiary of Malaysia Building Society Berhad (MBSB). It is a financial services provider in three core business areas: investment banking, development finance, and asset management.

Rhysida's Emergence and Operations

Rhysida is a RaaS that was first observed in May of 2023 and has become one of the more prevalent threats in the latter half of 2023. Rhysida engages in data exfiltration for double extortion and maintains both a leak site and a victim support portal on TOR. They are thought to be responsible for attacks against the Chilean military and, more recently, against Prospect Medical Holdings, which impacted services at hundreds of clinics and hospitals across the US.

FBI and CISA Advisory

In Q4-2023, the FBI and CISA released a joint advisory on Rhysida operations. Rhysida has been steadily increasing its attack volume and continuing to expand the targeted industries, but the volume is modest compared to that of its leaders.

Technical Analysis of Rhysida Ransomware

Rhysida deploys its ransomware through various methods, including Cobalt Strike or similar frameworks, as well as phishing campaigns. Analysis of Rhysida ransomware samples suggests that the group is still in the early stages of development. The ransomware lacks certain standard features, such as VSS removal, which are standard in contemporary ransomware. However, the group follows the practices of modern multi-extortion groups by threatening to distribute the stolen data publicly.

Upon execution, Rhysida displays a cmd.exe window and scans all files on local drives. Victims are instructed to contact the attackers using the TOR-based portal and their unique identifier provided in the ransom notes. The group only accepts payment in Bitcoin (BTC) and provides victims with instructions on purchasing and using BTC through the victim portal. Victims are also given an additional form on the payment portal to provide authentication and contact details to the attackers. The Rhysida ransom notes are written as PDF documents and placed in the affected folders on the targeted drives.