Threat Signal Report
Lightning Framework: A New Modular Malware for Linux
FortiGuard Labs is aware of the discovery of a new Linux malware variant that is not only complex in design, but modular. Dubbed 'Lightning Framework', the malware consists of various modules for different functionality. At this time, there is no report of Lightning Framework being used or observed in the wild attacks.
Why is this Significant?
This is significant because Lightning Framework is a previously unknown modular malware for Linux that can download and install different modules (including rootkits) and plugins to a targeted machine. While there are no reports of the malware being used in the wild, it can be safely surmised that the Lightning Framework can be expected and incorporated in real attacks soon.
What is Lightning Framework?
Lightning Framework is a modular malware that consists of various modules for different functionality.
A Lightning Framework infection starts with an installation of the Lightning.Downloader module on the compromised Linux machine. This module connects to its Command-and-Control (C2) server and is used to download other additional and plugins including Lightning.Core. Lightning.Core is the main module of Lightning Framework and is responsible for receiving commands from the C2 server and to execute remote commands.
Other modules that are downloaded by Lightning.Downloader are:
Linux.Plugin.Lightning.SsHijacker, Linux.Plugin.Lightning.Sshd, Linux.Plugin.Lightning.Nethogs, Linux.Plugin.Lightning.iftop, and Linux.Plugin.Lightning.iptraf.
According to the Intezer blog the modules: Linux.Plugin.Lightning.SsHijacker, Linux.Plugin.Lightning.Nethogs, Linux.Plugin.Lightning.iftop, and Linux.Plugin.Lightning.iptraf are referenced only in the source and actual files have not been discovered in the wild.
Furthermore, to add insult to injury - Lightning Framework can open a SSH backdoor using the Linux.Plugin.Lightning.Sshd plugin upon receiving a remote command.
What is the Status of Coverage?
FortiGuard Labs provides the following AV coverage against available modules and plugins of Lightning Framework:
Traffic Light Protocol
|Color||When Should it Be used?||How may it be shared?|
TLP: REDNot for disclosure, restricted to participants only.
|Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused.||Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.|
TLP: AMBERLimited disclosure, restricted to participants’ organizations.
|Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved.||Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.|
TLP: GREENLimited disclosure, restricted to the community.
|Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector.||Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.|
TLP: WHITEDisclosure is not limited.
|Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release.||Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.|