Within days after a report detailing the GoldenSpy malware operation targeting organizations doing business in China, an uninstaller was pushed to affected systems to completely remove the infection.
Last week, Trustwave published information detailing the manner in which a hidden backdoor had been delivered to organizations via Intelligent Tax, a piece of software from Aisino Corporation that is required by a Chinese bank.
Designed to provide attackers with unfettered access to the victim networks, with SYSTEM privileges, the GoldenSpy malware is believed to have been around since 2016, but it’s unclear how many organizations it might have compromised to date.
On June 28, just three days after Trustwave’s report went public, the Aisino Intelligent Tax product was observed silently pushing a new file onto infected systems, “AWX.exe.” This file was specifically designed to remove GoldenSpy and all traces of compromise, including registry entries and the malware’s files and folders, after which it would delete itself from the system.
The command used for deletion results in the Windows command-line interface being terminated upon the completion of the operation, and ensures that the deletion is performed without requiring permission or displaying a notification.
“In our testing, this GoldenSpy uninstaller will automatically download and execute, and effectively, will negate the direct threat of GoldenSpy in your environment, however, as the deployment of this uninstaller is delivered directly from the supposedly legitimate tax software, this has to leave users of Intelligent Tax concerned about what else could be downloaded and executed in a similar manner,” Trustwave notes.
Despite this new development, however, the security researchers are not convinced that the threat actor will slow down its activity, but rather consider it a “clear and present danger.” Thus, they advise organizations to remain vigilant and continue their threat hunting.
A second version of the GoldenSpy uninstaller was observed on June 29, only hours after the initial variant emerged. Identical to the first, the new iteration would obfuscate variables with Base64 encoding, likely in an attempt to evade detection.
Analysis of the uninstaller also revealed that it removes GoldenSpy following the exact malware removal steps that Trustwave included as recommendation in their report. This shows once again that the actor is fully aware of the attention it has received and wants to ensure it can hide its tracks to hinder further investigations.