Powerbook G4 Wolf Howl Around 6pm?

I've seen a few other people have posted in various sites about this problem. The 4 programs I have had open were iCal, Thunderbird, Firefox, and Skype. None of these are set to do a howling sound for any reason. I upgraded my Norton Anti-Virus software, scanned my computer and it was clean. I also ran MacScan. I had 41 tracking cookies, which I isolated. I also emptied all my email junk and trash folders. I did all this today, and so far no wolf howl (it happened the past three nights). I did read someone else's post saying that it happened to them between 6 and 8:30, so I'm not sure I'm in the clear yet. Does anyone know what this is caused by? I'm curious for the answer even if I have fixed the problem. :) Thanks!

Powerbook G4 Wolf Howl Around 6pm?internet

Since there are no MacOS X viruses, scanning for any was a waste of time. You really don't need Norton's, odds are it is slowing your Mac way down. I did computer tech for a school district for 10 years. High school students have a tendency to try to get around firewalls, security etc. In those ten years, I never had a Mac running MacOs X get a virus. You can set Firefox to delete all personal info when you exit it. Odds are you had a web page open in the background or downloaded a widget or other application that is similar. There is only one identified MacOs X malware. You have to visit a specific porn site, agree to download it, and then install it on your Mac. It's a fake ''codec'' to enable your browser to view video porn. The same malware is being distributed as a ''free anti-virus'' scan for Macs. Sounds like you have fixed whatever was the problem.