Is there a stand alone virus checker for MAC?

some suggest 'Bit Defender' and 'Virus Barrier Express'.

Do not install these.

There are many forms of ‘Malware’ that can affect a computer system, of which ‘a virus’ is but one type, ‘trojans’ another. Using the strict definition of a computer virus, no viruses that can attack OS X have so far been detected 'in the wild', i.e. in anything other than laboratory conditions. The same is not true of other forms of malware, such as Trojans. Whilst it is a fairly safe bet that your Mac will NOT be infected by a virus, it may have other security-related problem, but more likely a technical problem unrelated to any malware threat.

You may find this User Tip on Viruses, Trojan Detection and Removal, as well as general Internet Security and Privacy, useful: The User Tip seeks to offer guidance on the main security threats and how to avoid them.

https://discussions.apple.com/docs/DOC-2435

Klaus1 wrote:

some suggest 'Bit Defender' and 'Virus Barrier Express'.

Do not install these.

And why would that be Klaus?

Gatekeeper isn't an A-V. It's a level of restriction you apply to any downloads. Mac App Store only, software signed by a Mac developer with Apple, plus the MAS, and from anywhere. So the two aren't mutually exclusive, rather they may be comlimentary. XProtect is the built-in A-V like program on Macs. But you can run an A-V like VBE along with XProtect. XProtect is always running; it can't be disabled (well not by the average user, and I wouldn't know why anyone would want to.)

I really suggest you look at T. Reeds Mac Malware guide and other parts of his site. A lot of your questions are answered there. I already gave you a link, but here it is again.

http://www.reedcorner.net/mmg/

Yup, I'd agree with that. True malware may not exhibit any symptoms at all, and if it does have symptoms, there wouldn't be any predictable pattern to those symptoms. Flashback, for example, caused characteristic Safari crashes... But no other malware has injected code into Safari like Flashback did, so that particular symptom only matches one extinct bit of malware.

Avoid BitDefender. It won't hurt you, since it's from the App Store, but it won't do a very good job against Mac malware according to my testing:

http://www.thesafemac.com/mac-anti-virus-testing-01-2013/

VirusBarrier Express did quite well for me, as well as for the more recent test that I think someone else referred to already. I highly recommend that one. I also highly recommend Sophos, although that one installs some background components, so it could have an impact on performance and stability. It usually doesn't, but it could.

Don't download from CNet's Download.com. They have been known to inject adware into installers downloaded from their site. Avoid Softonic for the same reasons. If you decide to download something like Sophos, only download from the developer's site (Sophos.com).

As I read other comments with respect to my question, some suggest 'Bit Defender' and 'Virus Barrier Express'. What are those App's like and are they just as effective at the one you suggest.

As I wrote earlier, none of those applications is useful for detecting OS X malware, if you follow safe computing practices. That, and the built-in protections in OS X, are the only security there is. The "statistics" you might hear about are meaningless. Statistics about the effectiveness of Mac applications at detecting Windows malware may have a little bit of value, but not much. Detecting malware that is installed (and therefore more or less hidden) on a Windows system is very different from detecting it on an OS X system, where it can't be installed, and will almost always take the form of an email attachment or a file downloaded from a website. Windows malware is so widespread, and so rapidly changing, that you should suspect any unidentified email attachment of being malicious, no matter whether or not any software recognizes it as such. Never pass on such attachments unless you have opened them and verified that they're genuine. Most malware attachments are obvious, and those that are not obvious may well be too new or too sophisticated to be detected by software anyway.

The only real reason to install any kind of "anti-virus" software is to meet the requirements of a network administrator who falsely believes that such software is needed on a Mac. In that case, anything that satisfies the administrator is good enough.

You should certainly never pay a dime to protect Windows users from the consequences of their choice of computing platform. Use only free software, if you're going to use anything, and ignore the sales pitch to "upgrade" to a paid version.

One final comment. You mentioned "peace of mind." False peace of mind based on false security is the greatest danger you will ever face as a Mac user.

As I wrote earlier, none of those applications is useful for detecting OS X malware....

You might have said "not needed if...." (And that is open to debate.) But "not useful"? On the face of it that is an absurd statement.

You have confirmed my reservations on downloading anything other than from Apple's App site.

I didn't intend to send that message, exactly. There are plenty of perfectly legit and safe apps that don't come from Apple's Mac App Store. If you decide you want Sophos, for example, it is perfectly fine, so long as you download it from here:

http://www.sophos.com/en-us/products/free-tools/sophos-antivirus-for-mac-home-ed ition.aspx

So in your opinion, VBE would be a better choice than 'ClamXav'?

Definitely. ClamXav hasn't been testing so well lately, unfortunately.

Apple Support Communities is a public discussion forum. Your question may draw responses from more than person. Each one speaks only for himself or herself (apart from "Community Specialists," who speak for Apple), and they may disagree among themselves.

All responses should be understood as comments, not as technical support. The fact that someone answers your question doesn't mean that the answer is correct. Some of what passes for advice here is good, some is wrong, and some is nonsensical. Use caution, do your own research, and make backups before acting on advice from anyone.

"some is nonsensical"

The hosts censored you for basically calling WZZZ an idiot, so you decided to be a little more subtle, is that it? If you disagree with advice being given, counter it with facts and logical reasoning, not insults.

"...and some is nonsensical."

And you do realize that, since you are participating just like anyone else in this public discussion forum, anything you write, by definition, might be included in this category.

Meant for WZZZ.

I searched Mac App Store for VBE, clicked on the name when it came up and read the screen. Just shows how easily one can be mis-led when people like Thomas and yourself think highly of it.