Does anyone use extra antivirus software?

iRach

macrumors member
Original poster
Dec 11, 2009
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I was wondering as I read Macs have to have virus' downloaded and wondered if the built in Firewall is enough.

If so what do you recommend?

Thank you
 

miles01110

macrumors Core
Jul 24, 2006
19,264
30
The Ivory Tower (I'm not coming down)
Viruses won't affect your system (trojans will if you let them, though) but a virus scanner is still useful if you send files to Windows machines. ClamXav works well.

PS a firewall won't protect you on any system if you download malware yourself.
 

iRach

macrumors member
Original poster
Dec 11, 2009
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0
Thanks, I asked 'cause husband's pc just found a trojan, made me a bit nervous as the mac is new and I'm new to macs.
 

uberamd

macrumors 68030
May 26, 2009
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Minnesota
Viruses won't affect your system (trojans will if you let them, though) but a virus scanner is still useful if you send files to Windows machines. ClamXav works well.
I also suggest ClamXav which is free and easy to use. I often use my Mac to scan Windows hard drives and USB drives to remove viruses and what not.
 

NathanCH

macrumors 65816
Oct 5, 2007
1,053
0
Stockholm, Sweden
If you don't touch windows, no need what-so-ever. People claim there are viruses, but they have never been caught in the wild. If you want to waste money, buy virus protection for mac.
 

iRach

macrumors member
Original poster
Dec 11, 2009
98
0
Thanks for the replies everyone:)
Is the the Clamxav version i should download? ClamXav 2.0.5 Public Beta
 

disconap

macrumors 68000
Oct 29, 2005
1,800
2
Portland, OR
Stay away from Norton
This is true in EVERY POSSIBLE WAY with OSX. Norton has continually failed to provide any quality products for OSX whatsoever in my experience. Which is a shame, as they were basically the only company I'd ever trust with disc utilities and the like in OS7-9...
 

broken-chaos

macrumors regular
Sep 2, 2009
189
0
Toronto, Ontario
Trojans for OSX (not viruses or worms) have been, quite rarely, found in the wild -- such as the instance with the (pirated) iWork '08 download from a year or two back that had a trojan.

Anyway, the difference between a trojan, a virus, and a worm (three major forms that malware takes):

Trojan: A program that pretends to be something it's not -- for example, a download that claims to be a super-awesome screensaver, but actually makes your machine start sending out spam e-mails. These only ever occur as actual programs -- they just lie about what they do.

Virus: An infected file that infects a computer, which can copy itself to other files -- for example, a Word document that, when opened, copies itself to your other Word documents, as well as starting to do something evil in the background. These can occur in (theoretically) any file, including programs, but are rather rare and often have to exploit vulnerabilities in third-party programs on the host OS.

Worm: A program that is entirely, silently self-propagating, meaning it can, entirely automatically, copy itself to other computers, often by exploiting security vulnerabilities. These are also somewhat rare (though extremely wide-spreading and dangerous when they occur) and can sometimes be stopped cold by basic network security -- such as a firewall.

A prerequisite for stopping any of these things is to keep your computer fully-patched, and all third-party programs you run up-to-date. Doing this will stop a large percent of viruses and worms (no matter what OS you're running) dead in their tracks.

To avoid trojans, the best method is to only download software from trusted sources -- you'll have to determine for yourself who you can or cannot trust, though this can often be accomplished by a simple Google search or two. Trojans cannot be ever completely eliminated because they rely on the user to, in essence, do something stupid. All operating systems are vulnerable to trojans, and there isn't too much the OS can do about it (certainly not for home users). OSX does have a bit of protection built-in, mind you -- I believe Snow Leopard has a database of known OSX trojans (though it's trivial to write a new trojan), as well as having all the fanfare around quarantine and 'safe' files. There are too many trojans floating around to give a good example of a single one.

Avoiding viruses is a little tricker, since they can masquerade as normal files. Viruses are somewhere between 'exceptionally rare' and 'totally unheard of' for OSX, so you likely don't have much to worry about anyway. Even Windows viruses have somewhat fallen to the sidelines, often in favour of trojans. The best security to avoid any threat of them, however, is to scan downloaded files (especially from questionable sources) with a basic virus scanner (such as the aforementioned clamXav). It's probably not necessary, to be honest, but may be a good habit to be in anyway. Most ISPs and e-mail providers do scanning for viruses sent by e-mail, so you'll most-likely be entirely safe with e-mailed files. I can't think of an example of a recent virus, though some of the recent Adobe Reader vulnerabilities tend to mimic viruses in all except the self-copying.

Worms are the most difficult to avoid, if there's a vulnerability in a network service you use. The best protection you can do is to set your firewall on, all network services (in System Preferences -> Sharing) off, and turn your firewall onto stealth mode. Also, as I already mentioned, keep your computer fully patched. I've never heard of, even a proof-of-concept, OSX worm, and numbers of Windows worms have been declining with recent releases and patches. An example of a fairly-recent Windows worm is Conficker.

I hope my lengthy rambling is useful to someone. :p
 

iRach

macrumors member
Original poster
Dec 11, 2009
98
0
Lengthly rambling always welcome.:)

I thought about the ClamXav 2.0.5 Public Beta, because it said the other wasn't suitable for Snow leopard. Should I install the iAntivirus aswell, or just the Clamxav, and which version?

Sorry for all the questions but this all out attack on the pc had made me nervous:(
 

MacDawg

macrumors Core
Mar 20, 2004
19,708
4,274
"Between the Hedges"
Honestly, I wouldn't install either
But if I had to choose, I would install ClamXav and just go with the Beta
But don't install both, there is no reason
I don't think you will have a problem either way

Woof, Woof - Dawg
 

Tumbleweed666

macrumors 68000
Mar 20, 2009
1,650
47
Near London, UK.
Should I install the iAntivirus aswell, or just the Clamxav, and which version?

Sorry for all the questions but this all out attack on the pc had made me nervous:(
Bear in mind that Clam will not do anything about protecting your Mac, it may protect PC's to which you might send an email, which you received from another PC user, that had a virus - a long chain there, plus if those PC's dont have antivirus they will already be multiply infected, so whats the point? That virus BTW wont do anything at all to the Mac.

iAntivirus says 'it protects against Mac viruses' but since there arent any, its as effective as my cat in that respect.

Your husbands PC got a trojan either because (a) the tool he used falsely identified an application as a trojan when it wasn't (this isn't uncommon), or (b) he downloaded and installed a program from a compromised source. He'd do better to be more careful about what he installs, and if you are, you dont need any additional programs to monitor. If you arent going to be downloading and installing applications from dubious websites, you dont need anything that looks for Trojans, full stop. (Mac already does this anyway)
 

iRach

macrumors member
Original poster
Dec 11, 2009
98
0
Thanks, I rarely download anything and never anything I'm not totally sure of, even double checked with you all about downloading ClamXav! The odd thing is he hasn't downloaded anything apart a font from dafont, it appeared and removed his desktop picture and everytime he clicks on a website it redirects him to somewhere else. Sound familiar to anyone?
 

itsbrad

macrumors newbie
Jan 2, 2010
8
0
Eh, I go to some shady websites so just for peace of mind I installed a Norton that I already had.
 

Tumbleweed666

macrumors 68000
Mar 20, 2009
1,650
47
Near London, UK.
Thanks, I rarely download anything and never anything I'm not totally sure of, even double checked with you all about downloading ClamXav! The odd thing is he hasn't downloaded anything apart a font from dafont, it appeared and removed his desktop picture and everytime he clicks on a website it redirects him to somewhere else. Sound familiar to anyone?
http://forum.zazzle.co.uk/misc/warning_dangerous_font_site_dafont_com

"WARNING: DANGEROUS FONT SITE!!!! (DAFONT.COM)"
 

Ardoptres

macrumors regular
Dec 12, 2009
161
0
I've used ClamXav in the past and found about 2 infected files so far. I don't know if they've ever done anything, bad at least they're gone now..
 

Tumbleweed666

macrumors 68000
Mar 20, 2009
1,650
47
Near London, UK.
I've used ClamXav in the past and found about 2 infected files so far. I don't know if they've ever done anything, bad at least they're gone now..
Well they certainly wont have done anything to your Mac. You might want to inform the source, if it was a friend or company you know who sent it, that their Windows PC is infected.
 

Vortexboy

macrumors newbie
Mar 24, 2010
14
0
Should I get something more to actually delete viruses?

My Mac has been behaving strangely of late, such as:

1. Being very slow to respond to mouse clicks
2. It takes several seconds or more to react
3. Screen draws are slow
4. The application icon in the dock (such as Firefox) "stutters" or bounces a bit erratically as the program loads, etc.

The fan seems to be running all the time too.

I have Macscan and ran it but it didn't find anything.
Then I read about ClamXav and ran this program on my system, apps and utlis folders.

It found about 120 files with WM.Cap.A., which I found out is a virus that affects macros in Word files (which I don't have any of).
It also quarantined about 50 emails which I also deleted.

I deleted the documents (some of which I didn't want to and can't recreate) but now I am concerned and since ClamXav doesn't remove viruses, should I get something like Kapersky to protect my computer?

I've had my Mac for about 6 years and have not had any problems like this, so I am puzzled why this has happened now?