How do I know if my computer has a virus, and what can I do about it.

If you have a security program installed, such as Mcafee, the program should alert you if it’s discovered one.

yeah, because there’s like tons of virusses for OS X… now for the real answers, let’s just do some checks, once again, i’m camiel, your guide into the wonderfull world of OS X

in the user preferences there’s a tab called Login Items, go ahead and check out if there’s a lot in there, and if you really need it

next thing we could do is turn on the activity monitor, see what’s hogging up all that resource, as you can see, you can sort by various criteria, this appl can be found in /Applictions/Utilities

and if you’re still thinking of viruses on a mac, you must be a short time switcher….

Restart it.. There aren’t really any known bad things for a Mac floating around. Here is a tip from here that might help. That will help clear up some cruft.

In the terminal you could run:

Using your Admin account, you can execute all three maintenance scripts at once, as follows:

1. Launch Terminal, in the Macintosh HD > Applications > Utilities folder.
2. At the Terminal prompt, type the following, exactly as written:
sudo periodic daily weekly monthly
3. Press Return.
4. Type your Admin password when prompted, then press Return.

All three scripts will run in sequence. There is no visual feedback while the scripts execute. You will know they are completed when the Terminal prompt returns.

Ask me, I’ll tell you ;) You don’t have any viruses.

Ok, woh. This is a lot. I’m going to try this stuff and get back to you.

I’ve been using Mac since 2002, but I use it for music, internet and word processing, that’s about it. So you’re saying that Macs don’t really get viruses? That’s good to know.

Check the Apple support site and make sure that any EFI firmware updates have been installed (search support with EFI firmware and MacBook in the search box)

You can also zap the PRAM by restarting while holding down P R Command and Option keys.

Also have you checked out how full your internal system drive is? You could be reaching max if it is any more than 80 percent full; remember that the OS uses a portion of the hard drive space as virtual memory, which when not available can severely slow down System processes.

@tinyfaery
OS X requires you to enter your administrator password to modify the system. If you don’t let applications like MacOSXTrojan use your password, you don’t have anything to worry about, just keep up with the Software Updates.

Oh yeah-crunchaweezy reminded me of something: There is some virus that is floating around out there that is propagating under the guise of a Flip4Mac updater, that appears as a pop-up window from an offending website when a page loads; it looks like a wmv is attempting to open but in the process a pop-up window appears saying your wmv player plug-in is out of date and a new one is being patched (paraphrasing). It then prompts for a password from within the browser (an admin password) in order to proceed with the update (which in fact installs the Trojan Horse)...it’s been seen in the wild, and can be dealt with using most off-the shelf anti-virus software. But beware if any sites you load in your web browser prompt you for plug-in updates!!! Always update your plugs from the companies that make them (their official sites).