Sftp.exe

sftp.exe is a Windows command-line utility that uses the Secure File Transfer Protocol (SFTP) to securely transfer files between a local machine and a remote server.

Execute

Proxy execution of specified command, can be used as a defensive evasion.

sftp -o ProxyCommand="{CMD}" .

Spawns ssh.exe which in turn spawns the specified command line. See also this project's entry for ssh.exe. — MITRE: T1202 — Privileges: User