A recent supply chain attack has come to light, involving the Free Download Manager software used by Linux users. Kaspersky, during its investigation, discovered that some Linux users were redirected to a malicious Debian package repository, which surreptitiously installed information-stealing malware on their systems.
This malware created a reverse shell connecting to a command-and-control server and deployed a Bash stealer, which harvested sensitive user data and account credentials. What’s particularly concerning is that this campaign has been active for over three years, yet the software vendor has not responded to Kaspersky’s report, leaving the precise method of compromise unclear.
The supply chain attack was selective, redirecting some users to the malicious Debian package repository while not affecting others when they attempted to download the Free Download Manager software from the official site. The malicious domain, “deb.fdmpkg[.]org,” was spread through various online platforms, including social media, Reddit, and more, masquerading as a legitimate source for Free Download Manager downloads.
Although the redirection activity seems to have ceased in 2022, older YouTube videos demonstrate users inadvertently downloading the malicious version. This malware is adept at collecting a wide range of sensitive data, including browsing history, passwords, authentication keys, and account credentials for cloud services like AWS and Google Cloud.
Despite the extended duration of the attack and the potential exposure of Linux users to the malicious package, its detection was hampered by the rarity of Linux malware and the fact that only a portion of users were redirected to the unofficial URL.
Users who installed the Linux version of Free Download Manager between 2020 and 2022 are advised to promptly check for the presence of the malicious version and remove any related files to mitigate potential data theft and security risks.