No Sam, dont panic, I'm not sure what it is but other people have had this problem on here, it's NOT a virus, (we call it the squiggles) Someone will probably be on soon to help, I just wanted to reassure you :-)
If your computer gets infected you can use
Norton, AVG , Avast are widely antivirus
software. You can download these
free softwares at http://tinyurl.com/yahtjk