If, as your log seems to indicate, the packet originated with your system, then you need to figure out not "which website is sending such an attack" but what (or who) on your system is generating the traffic.
Now with that out of the way, TCP port 10080 is most often used by the Amanda backup system. If you have set up Amanda to back up your server to a remote host, then this may be what is causing the traffic (and if it's blocked, then your backups aren't working!).
(Some PC games also use TCP port 10080, but I presume you aren't playing PC games on this Linux box...)
To find out who initiated the connection, modify each of the firewall logging rules to add
--log-uid. The user ID which initiated the connection will then be logged as
UID=###. An example:
iptables ..... -j LOG --log-uid ...