SALTWATER
Intelligence Profile
According to Mandiant, SALTWATER is a module for the Barracuda SMTP daemon (bsmtpd) that has backdoor functionality. SALTWATER can upload or download arbitrary files, execute commands, and has proxy and tunneling capabilities. The backdoor is implemented using hooks on the send, recv, close syscalls via the 3rd party kubo/funchook hooking library, and amounts to five components, most of which are referred to as "Channels" within the binary. In addition to providing backdoor and proxying capabilities, these components exhibit classic backdoor functionality.
Threat Analysis
SALTWATER is a malware family tracked by threat intelligence researchers and catalogued in the Malpedia dataset. It represents a distinct malicious software lineage with identifiable code characteristics, behaviors, and victimology.