I prefer using rsync to scp when copying files via jump hosts, for example, to target-host via the intermediate host jump-host:
rsync -v -e 'ssh -A -t [email protected] ssh -A -t target-host' nasty.file :/tmp
rsync syntax is stable across versions and platforms while the syntax of SCP is different across platforms and versions.
-A Enables forwarding of the authentication agent connection. This can also be specified on a per-host basis in a configuration file. Agent forwarding should be enabled with caution. Users with the ability to bypass file permissions on the remote host (for the agent's UNIX-domain socket) can access the local agent through the forwarded connection. An attacker cannot obtain key material from the agent, however they can perform operations on the keys that enable them to authenticate using the identities loaded into the agent. -t Force pseudo-terminal allocation. This can be used to execute arbitrary screen-based programs on a remote machine, which can be very useful, e.g. when implementing menu services. Multiple -t options force tty allocation, even if ssh has no local tty.