i was hacked?

Hail List! For at least 4 hours i was nacked .. without firewall .. i added a line and i misspell - whith = ... Now all seems to work but i,m worried! i don't know where to look to find if someone have done something evil to my router! i had ssh, smtp (postfix), cups, squid, xntp, mysql, snmp running at that time! So..please help!