Virus curiosity

Discussion in 'Mac Basics and Help' started by BexXx, Mar 8, 2010.

Thread Status:
Not open for further replies.
  1. BexXx macrumors newbie

    Feb 28, 2010
    Hi there, I've only had my macbook for couple months now and I've been hearing constantly that macs can't get viruses. Fair enough, but I live with non mac fans who keep telling me that this isn't possible and that somewhere someone will have created viruses for macs.

    Seeing as I don't really understand the science behind it (to put me at ease) would someone please explain to me if it is possible to get a virus and if not then why? What's the technology behind it?

    Kind Regards

  2. robbieduncan Moderator emeritus


    Jul 24, 2002
    Nothing is impossible. But, to date, there have been no viruses for Mac OSX. By virus I'm using the "correct" definition: a self-replicating, spreading piece of unwanted code that can transfer from system to system without any user intervention.

    There have been a small (<20) number of trojans that rely on the user downloading them and typing in an admin username and password by "tricking" the user (often by claiming to be an installer for a pirated piece of software).

    So, to date, as long as you don't download stuff from dodgy sites and give it your admin username and password you will be fine.

    Why is this the case? No specific technology. Unix, by it's nature, is more secure than Windows was in the past as users don't run as root. Much of the lower levels of OSX are very old, well tested and in places open source so there are far fewer exploitable bugs.
  3. angelwatt Moderator emeritus


    Aug 16, 2005
    There are viruses for Mac, just not Mac OSX (nothing beyond proof-of-concept anyway). As mentioned above, there are a few trojans running around, but are pretty easy to avoid. The bigger things you need to worry about is falling for social engineering attacks that trick you into giving up your personal information to a malicious group. The OS can't protect you from these attacks (known as phishing) very well so require users to be cautious for their own sake.
  4. GGJstudios, Mar 8, 2010
    Last edited: Jan 6, 2014

    GGJstudios macrumors Westmere


    May 16, 2008
    Mac Virus/Malware Info

    Link to this post: Mac Virus/Malware Info

    You DON'T have a virus on your Mac!
    If you want to know why this is true, read on.

    The term "virus" is commonly but erroneously used to refer to all types of malware, adware, and spyware programs that do not have the reproductive ability of a true virus.

    The bottom line is this: as a Mac user, your chances of being affected by a virus, trojan or other malware are extremely slim, unless you've been careless about where you get software and when you enter your administrator password.

    If you're experiencing a problem or unexpected behavior with your Mac, there's better than a 99.9% chance that it's something other than a virus or other malware.

    From Symantec:

    What is scareware?
    Another type of hoax is referred to as scareware. It's a bogus virus warning that pops up when visiting some websites, and looks something like this or this (on iPads). If you take a close look, you'll see the popup refers to a Windows system, which obviously doesn't relate to Mac OS X. It can't harm your Mac at all. Just close the site, clear your browser's cache and cookies, and you'll be fine. Sometimes these scareware sites will generate a never-ending loop of popups, to the point that you must Force Quit your browser. Such scareware sites are usually intended to lure a Windows user into clicking the links to install bogus "antivirus" software, which is typically a trojan. Even if you click the links on a Mac system, it can't install anything, because Windows executable files can't run on Mac OS X.​

    There are NO viruses in the wild that affect Mac OS X at this time.
    If this changes, I will update this post. According to noted computer virus expert Paul Ducklin, in order for a virus to be considered in the wild, "it must be spreading as a result of normal day-to-day operations on and between the computers of unsuspecting users." This definition excludes "proof of concept" code that is used in a testing situation under strictly controlled conditions, and which poses zero threat to average computer users.

    In the past, there have been a few viruses that ran on older versions of the Mac operating system (Mac OS 9 and earlier), but they do not run on any version of Mac OS X. Like every other OS, Mac OS X is not immune to malware threats, this situation could change at any time, but if a new virus is discovered, the news media, forums, blogs, etc. will be instantly buzzing with the news. See update below.*

    There are trojans that can affect Mac OS X,
    but these must be downloaded and installed by the user, which usually involves entering the user's administrator password. Also, Mac OS X will give you a warning when you first launch an app you downloaded from the web. Trojans can easily be avoided by the user exercising common sense and caution when installing applications. A common source of trojans is pirated software, typically downloaded from bit torrent sites.​


    Having virus protection software on your Mac is pointless, as far as protecting your Mac from true viruses, since current antivirus software cannot detect a Mac virus that doesn't yet exist, because they simply don't know what to look for. It is possible to have a virus-infected file reside on your hard drive, but since a Windows virus (like any Windows program) can't run in native Mac OS X, it would be harmless to your Mac and could not spread.

    If your situation requires you to run a 3rd-party antivirus app:
    • ClamXav is one of the best choices, since it isn't a resource hog, detects both Mac and Windows malware and doesn't run with elevated privileges. You can run scans when you choose, rather than leaving it running all the time, slowing your system. ClamXav has a Sentry feature which, if enabled, will use significant system resources to constantly scan. Disable the Sentry feature. You don't need it. Also, when you first install ClamXav, as with many antivirus apps, it may perform an initial full system scan, which will consume resources. Once the initial scan is complete, periodic on-demand scans will have much lower demands on resources.
    • Sophos should be avoided, as it could actually increase your Mac's vulnerability, as described here and here... and here.
    • iAntiVirus has a bogus malware definitions list, making their detection accuracy untrustworthy. They also make inaccurate claims about the existence of Mac malware, in order to hype the need for their product. This post will give details.


    • DON'T install pirated software, or software from untrusted or unknown sites.
    • You can't infect your Mac simply by visiting a website, opening an email attachment, or connecting to a network. You should, however, exercise reasonable caution when doing these things.
    • Be careful about giving others access to your computer, as they could download and install malware.
    • For Safari users: go to Safari > Preferences > Security > Enable Java (leave this unchecked, unless you're visiting a trusted site that requires it)
    • Make sure you install software updates when they're released, including OS X and apps
    • Only install updates from an installed app, the Mac App Store or directly from a software developer's site. Never install an update to software when prompted to do so by an advertisement on a website or an email.
    • Use ad-blockers to minimize exposure to malicious sites
    • Use trusted DNS servers
    • Go to System Preferences > Security > Firewall and make sure your built-in firewall is enabled
    • Read Mac Security Suggestions compiled by munkery

    Some users choose to run antivirus such as ClamXav on their Mac to scan for Windows viruses (it also scans for Mac threats), so the Mac user can't pass a virus-infected file to a Windows user. However, a more prudent approach is for every Windows user to be protected by their own AV software, to guard against viruses from any source, not just those that might come from a Mac user.

    Running anti-virus on your Mac to protect Windows users from malware is like covering your mouth when you cough in front of the kids, then sending them out without flu shots to a school where a flu epidemic is spreading like wildfire. Great! They might not catch anything from you, but you've left them vulnerable to the greater risk. It's wiser to make sure they have flu shots, so they're protected from infection, whether it be from you or from other people.

    If you really want to help your Windows friends, encourage them to get their own anti-virus protection installed, or offer to install it for them.​

    Some users experience a problem with being directed automatically to sites that they didn't intend to visit. This may also occur when searching with Google. You don't have a virus! It's a problem with your DNS settings, either in your Mac or in your router. Try resetting your router. Here's how to fix the problem in Mac OS X:


    As has already been stated, any appearance of significant new security threats to Mac OS X will make news headlines:

    MacDefender or MacSecurity or MacProtector or MacGuard installation package
    Apple has issued a knowledge base article on this issue, found here:

    How to avoid or remove Mac Defender malware
    Further information on MacDefender:

    trojan.osx.boonana.a Trojan
    On Oct. 26, 2010, Mac security site SecureMac posted this security bulletin:
    As with all trojans, this requires the user to unwittingly invite the infection by deliberate action (in this case, clicking on a fake video link). You cannot be infected by this trojan if you don't click on the appropriate link. You can eliminate this threat by disabling Java in your web browser.
  5. Buzz Bumble Guest

    Oct 19, 2008
    New Zealand
    Everyone else has already covered the non-existance of viruses on the Mac, so it simply remains to say: tell the people you live with that they're idiots who know nothing about Macs. ;)
  6. -aggie- macrumors P6


    Jun 19, 2009
    Where bunnies are welcome.
    Correct me if i'm wrong, but I thought the main reason there were no Mac virii, was due to the fact that there are much less Macs than Windows computers, so the hackers don't feel the need to waste their time. The OP was asking if there is something about the operating system that makes it impossible.
  7. Mac'nCheese macrumors 68040


    Feb 9, 2010
    Some people would claim that there has been one or two viruses for os X.

    However, others call those viruses "worms" and they don't count.

    I did notice that those who love their macs get more offended by even the suggestion of a mac virus then if you had said their mothers have viruses.
  8. Mac'nCheese macrumors 68040


    Feb 9, 2010
    There might be another reason (the os) for why there aren't any current, known, in the news, etc. viruses, but you hit the nail on the head. Us mac users are the smart minority in the computing world.... why would hackers waste the time to eff with just a few people when a pc virus can spread and wreck havoc on millions and millions of people.
  9. Hmac macrumors 68020

    May 30, 2007
    Midwest USA
    On the contrary IMHO. The "no virus on Macs" thing is repeated so often around the tech world, and Macs tend to be so hated by the general run of the PC community, that the first guy to create a successful virus for the Mac would be famous. I think there's PLENTY of stimulus to have done that by now if it were reasonably easy.

    I think that after all these years of increasing Mac sales, increasing Apple prominence, and increasing "no-virus" bragging, we would have seen a Mac virus long before now.
  10. Mac'nCheese macrumors 68040


    Feb 9, 2010
    But to be famous, the guy who created it would have to go public and if he did.... wouldn't he get charged with some kind of crime or at least beat to death by macheads?
  11. patrick0brien macrumors 68040


    Oct 24, 2002
    The West Loop

    As phrased, you may very well be right, the main reason. However, with the Mac's popularity on the upswing, that assertion, while having a small grain of truth to it is losing its footing. It is also indeed true that some attempts at hacking Macs have been successful, but, with the exception of the afore-mentioned trojans, only in the lab under very specific conditions - like being on the same subnet.

    Mac users will likely see a rise in attacks, but knowing UNIX underpinnings, i would be monumentally surprised at a proportionate rise in breaches. UNIX was specifically built to support a network, and to be shut down very very rarely. Windows was and still is neither.

    Not "impossible", but very very difficult. So difficult that until there is a really compelling need, like a lot of money on the line, hackers will tend to concentrate on Windows. (note, the "compelling need" I refer to is not popularity, but the value of what the OS is protecting)
  12. Consultant macrumors G5


    Jun 27, 2007
    The Unavoidable Malware Myth

    Market Share Myth
  13. -aggie- macrumors P6


    Jun 19, 2009
    Where bunnies are welcome.
    Thanks for both of your replies. I'll try to make sure to quash these myths in the future.

    FYI, I first saw those myths on MacRumors. :)
  14. notjustjay macrumors 603


    Sep 19, 2003
    Canada, eh?
    The Mac is no more "magical" an operating system than any other Unix variant, including Linux.

    Note how very few viruses exist for any of those platforms, as well.

    In fact, the only major modern computing platform for which there is a serious virus threat, is, well, created by one particular software company.

    I do recall, back in the days of System 6 and System 7, labs full of Macs at my high school, every one of them infected with CDEF or nvir.B. But that was 1992. ;)

    As OS X continues to gain prominence and market share, one day someone will discover a security vulnerability and actually do something damaging with it, as opposed to simply making a lot of noise and demonstrating a benign proof-of-concept until Apple releases a patch. But in 10 years of OS X, that day has not yet come...
  15. BlueRevolution macrumors 603


    Jul 26, 2004
    Montreal, QC
    The "security by obscurity" argument is unfounded as far as I'm concerned. Yes there are fewer Mac users, but they're also smug about their systems' invulnerability. If I were writing viruses, I would specifically target Macs, just to show them that pride goeth before the fall. And yet there are still no Mac viruses out there.
  16. Kauai macrumors 6502a

    Oct 13, 2010
  17. Dr McKay macrumors 68040

    Dr McKay

    Aug 11, 2010
    People will go for the weak link. Windows.

    Although for the 2nd year in a row, OS X fell within 10 seconds in the Pwn2Own contest, the hacker gained full access to OS X merely by the target computer visiting a certain website.

    So while there may not be viruses, it seems to be startlingly easier for a hacker to gain control of OS X.
  18. Apple OC macrumors 68040

    Apple OC

    Oct 14, 2010
    is that list not put out by an AntiVirus company ... the bottom line is

    If there was a major threat concerning a virus for OSX ... forums like these would be exploding with information about it.
  19. GGJstudios macrumors Westmere


    May 16, 2008
  20. kuebby macrumors 68000


    Jan 18, 2007
    I read about that too. But it had taken them months to come up with the exploit, whereas a few years ago it only took a few hours to find a hole in Safari to exploit.

    It should also be noted that Internet Explorer fell just as fast. Chrome was supposed to be tested yesterday as well but the hacker didn't show up (possibly because their exploit was just patched in the recent update).
  21. Jethryn Freyman macrumors 68020

    Jethryn Freyman

    Aug 9, 2007
    Currently no known viruses exist for Macs.

    The end.
  22. Tumbleweed666 macrumors 68000


    Mar 20, 2009
    Near London, UK.
    How about, they'd bother because Mac owners are on average more affluent, plus none of them have any anti virus protection, so such a virus would spread unhindered in an environment where statistically there is ore money to be stolen. To propose its simply a numbers game, means that every single virus writer believes that and behaves identically, obviously a ludicrous proposition. It would mean there is not even one single virus writer targeting Macs. Do virus writers all belong to the same club and do the same thing?

    In fact, thinking about it, that idea is provably false as there is malware that targets Mac, just not viruses. So why is it the people creating that malware arent also writing viruses, as they obviously think Macs are worth attacking? The obvious answer is, that to date, they haven't worked out how to do it.
  23. teknoscott macrumors newbie

    Aug 27, 2012

    I am having this same issue, being redirected to The Click Check.....GGJStudios I read your post but I still need help! When I go to reset my DNS settings, they are greyed out. You refer to this:

    "If any of the DNS servers are greyed out after entering your admin password, refer to this: 10.5: Disable DHCP-specified DNS servers"

    I don't get it though, even after I read it. Not too familiar with my Mac or computer terminology...can you help me please?
  24. GGJstudios macrumors Westmere


    May 16, 2008
    What DNS settings does it show? You should be able to add the OpenDNS servers, in addition to the ones you have.
  25. teknoscott macrumors newbie

    Aug 27, 2012
    I took some screenshots. I changed the DNS to what was explained in the earlier post, but the redirection is still happening. Is the issue something else?

    I also used DNSChanger tool to scan, and it said nothing was found.

    Attached Files:

Thread Status:
Not open for further replies.

Share This Page