Hi Alfredo and Welcome to SCF Community.
Don't worry We'll help you to remove this nasty worm.

Hakaglan, also referred to as W32/Hakaglan.worm.gen, is a computer worm spread through Yahoo Messenger and removable drives, such as USB flash drives. Hakaglan has the ability to copy and spread itself from one computer to another without the help of a human. One way it may do this is by accessing your email address book and sending itself to all of your contacts.
Now please follow my instructions:
1. Run BitDefender or Panda Online AntiVirus Scan:
http://scforum.info/index.php/topic,734.0.html2. Download & run HijackThis:
http://scforum.info/index.php/topic,785.0.html3. Provide us logs from HijackThis & AntiVirus Online Scan
I'll wait your reply (with logs).
Regards,
Samker