My Linux PC has been hacked once and attempted a second hack. What do I do?

[Timbuck]

Ubuntu 12.04 is out and Unity is SOOO much better you may want to upgrade
It is supported for 5 years
Did you explain to your friend that HE/SHE IS A COMEPLETE DUMASS AND THAT YOU SHOULD NEVER EVER SAY STUFF LIKE THAT JUST JOKING AROUD OR NOT
well i think you should disconnect or turn off your MODEM the shabang
Then get on another device with net and find out how to SECURE a linux machine
I probably should too um and install wireshark
Btw i really think your friend may have pissed off a few people
I have an idea --- let them connect
Open Libre office Writer and tell them it was 'the other guy/ga/' and SINCERELY appologize to them and try to explain that you were not being serious---- and DO NOT let it happen again
Btw i think this is the best way i mean just say sorry and i think they will be ok