<\/a><\/figure>\n\n\n\nKTLVdoor masquerades as different system utilities, including sshd, Java, SQLite, bash, and edr-agent.<\/p>\n\n\n\n
Upon executing the backdoor, it continuously communicates with its C2 server, awaiting instructions. It supports commands for downloading\/uploading files, exploring the file system, launching an interactive shell, executing shellcode, and conducting various scans (e.g., TCP, RDP, TLS, Ping, Web). <\/p>\n\n\n\n
The communication relies on GZIP-compressed and AES-GCM-encrypted messages. Each message can be delivered in simplex mode (one device on channel can only send, another device on the channel can only receive) or in duplex mode (both devices can simultaneously send and receive messages).<\/p>\n\n\n\n
It is still unclear how Earth Lusca distributes the new backdoor KTLVdoor.<\/p>\n\n\n\n
“We have been able to tie samples of KTLVdoor to the threat actor Earth Lusca with high confidence. However, we were not able to tie several other samples of this malware family to this threat actor. In addition, the size of the infrastructure we have been able to discover is very unusual.” concludes the report that includes Indicators of Compromise (IoCs). “Seeing that all C&C servers were on IP addresses from China-based provider Alibaba, we wonder if the whole appearance of this new malware and the C&C server could not be some early stage of testing new tooling.”<\/em><\/p>\n\n\n\n