Urgent, need help please!!

Hi guys, made a mac forums account purely for this. Not long ago I was doing stuff online and decided to stop, and started doing something else. About 20 minutes later, I went onto youtube and then it was all static then looked like por* was on the screen, and since then, changed to the skype call I had earlier with my friend and I can't see anything else on the screen but that. I really need to fix this, please reply as soon as possible as to what it is and how to fix it.

Note: I have a virus scanner (clamxav, from app store) currently running and its picked up two things both with the infection name of 'win-trojan.ramnit-690'

Edit: Just checked chrome and firefox, I don't seem to be having any problems with those two browsers, only safari. I don't know if it's only youtube though.

Its not a virus, and that trojan you mentioned is a windows bit of malware

I know this is from page 1 of the IT manual, but have you tried restarting?

As louishen stated, it is not virus.

Any of the followings may be the cause;
System Congestion, drivers may need update, flash and browsers may need update, it could be RAM and Graphic Card issue as well.