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Whats a good free virus, malware scanner for Mac OS X?

Discussion in 'Mac OS X 10.7 Lion' started by SRLMJ23, Jul 4, 2012.

  1. macrumors 6502a

    I think I might have some virus or malware and I'd like to scan my Mac but I'm new to OSX so I don't know any free scanners that are reliable. Any help would be greatly appreciated. Thanks in advance!
  2. macrumors demi-god


    What makes you think you have malware?

    Macs are not immune to malware, but no true viruses exist in the wild that can run on Mac OS X, and there never have been any since it was released over 10 years ago. The only malware in the wild that can affect Mac OS X is a handful of trojans, which can be easily avoided by practicing safe computing (see below). Also, Mac OS X Snow Leopard and Lion have anti-malware protection built in, further reducing the need for 3rd party antivirus apps.
    1. Make sure your built-in Mac firewall is enabled in System Preferences > Security > Firewall

    2. Uncheck "Open "safe" files after downloading" in Safari > Preferences > General

    3. Disable Java in your browser (Safari, Chrome, Firefox). This will protect you from malware that exploits Java in your browser, including the recent Flashback trojan. Leave Java disabled until you visit a trusted site that requires it, then re-enable only for the duration of your visit to that site. (This is not to be confused with JavaScript, which you should leave enabled.)

    4. Change your DNS servers to OpenDNS servers by reading this.

    5. Be careful to only install software from trusted, reputable sites. Never install pirated software. If you're not sure about an app, ask in this forum before installing.

    6. Never let someone else have access to install anything on your Mac.

    7. Don't open files that you receive from unknown or untrusted sources.

    8. For added security, make sure all network, email, financial and other important passwords are long and complex, including upper and lower case letters, numbers and special characters.

    9. Always keep your Mac and application software updated. Use Software Update for your Mac software. For other software, it's safer to get updates from the developer's site or from the menu item "Check for updates", rather than installing from any notification window that pops up while you're surfing the web.
    That's all you need to do to keep your Mac completely free of any Mac OS X malware that has ever been released into the wild. While you may elect to use it, 3rd party antivirus software is not required to keep your Mac malware-free.

    If you still want to run antivirus for some reason, ClamXav (which is free) 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.
  3. macrumors 6502a

    I think I have something because every now and then something pops up on my desktop but it pops up so quick I can't even see what it is...I don't know if its part of a program I have installed (I was thinking MS Outlook) but who knows...id rather scan and be safe than have something and do nothing about it.

    Any thoughts???
  4. macrumors demi-god


    Unless you've been installing pirated software or careless about entering your admin password, your chances of having malware on your Mac are extremely slim. There are many legitimate reasons why something could pop up, without malware being involved. Unless you know what the popup is, it's difficult to know for sure.

    1. Launch Activity Monitor
    2. Change "My Processes" at the top to "All Processes"
    3. Click on the CPU column heading once or twice, so the arrow points downward (highest values on top).
    4. Click on the System Memory tab at the bottom.
    5. Take a screen shot of the whole Activity Monitor window, then scroll down to see the rest of the list, take another screen shot
    6. Post your screenshots.
  5. macrumors 6502a

    Stupid question but how do I take a screenshot??
  6. macrumors demi-god


    Did you try clicking the link I posted? Click on the words "screen shot" in my post.
  7. macrumors 6502a

    Here you go, hope I did it right. Also, the scan came back negative for any malware/virus'.

    Attached Files:

  8. macrumors demi-god


    I'm not surprised. As I said, malware is not your problem. I don't see anything running that would contribute significantly to slow performance. However, you've got some page outs showing in your System Memory tab, which could indicate a need for more RAM. You have 2GB, which is pretty low for many users, especially running Lion. If the computer you're using is the MBA in your signature, you're stuck with the RAM you have, so you'll have to take some steps to get the most out of the resources you have. This may help:
  9. macrumors 6502a

    I haven't restarted in a while, however, I have a MacBook Air 2011 and was under the impression that I could not add RAM...so I guess I am stuck with the 2GB (unless you tell me different.) I really appreciate your help at least I know that nothing is wrong with my Mac which I absolutely LOVE!
  10. macrumors demi-god


    As I said, you're stuck with the RAM you have. Go through the performance tips. That should help.
  11. macrumors 6502a

    I restarted and have several programs open that I use almost all the time and my "page outs" is currently at 0 bytes...system has been up and running for about 15 minutes so maybe I am good there?? I'll go through your performance tips and see what I can do. I appreciate your help bro, thank you so much!
  12. macrumors 6502a

    Another question: Is there a way to stop OSX from turning off my Wi-Fi when my computer goes to sleep or whatever it does after like 10 minutes. When it turns back on from sleep the wi-fi has to reconnect and though it only takes a few seconds id prefer it to be connected at all times.
  13. macrumors demi-god


    There's no way your computer can remain connected to WiFi when it's in sleep mode. You just have to be patient to wait a few seconds after waking, so it can reconnect.
  14. macrumors newbie

    i think i may have malware how could i check for it?


    What did you use to scan for malware?
  15. macrumors demi-god


    What makes you think you have malware? You can use ClamXav to scan for malware.
  16. macrumors newbie


    I use Sophos it's great it blocks pages that have threats to your mac and protects your mac really well and there's also another one called avast!
  17. macrumors demi-god


    I recommend avoiding Sophos, as it can actually increase a Mac's vulnerability, as described here and here. 3rd party antivirus apps are not needed to keep a Mac malware-free, as long as the user practices safe computing, as described in the following link. If you need to perform a scan for some reason, ClamXav (which is free) 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.

    Also, websites do not threaten your Mac. Failure to practice safe computing does.
  18. macrumors member


    What about the akamaihd malware? Does it count as infecting the OS or the browsers? Would Noscript for Firefox block it?
  19. macrumors demi-god


    It is a JavaScript that runs in the browser. It does not affect OS X, but rather redirects your browser to unwanted sites. Resetting your browser, clearing the cookies and cache should remove it. NoScript may block it, but I haven't tried it, as I use Safari.
  20. macrumors demi-god


    That is adware and you likely got tricked into installing it along with the GoPhoto.it Firefox extension.

    You can either remove it manually following this guide. Or you can use the adware removal tool here to do it for you. Note the section in the middle of the page talking about GoPhoto.it.
  21. macrumors member

    Akamaihd solved with Noscript

    Thanks for the help. Noscript sure seems to help. The odd thing is I have to allow akamaihd.net to get Facebook to load photos. It was fbstatic.akamaihd that was stopping Facebook from loading at all.
  22. macrumors 6502a


    Sadly, Clam doesn't detect every Mac malware :(
  23. macrumors demi-god


    No antivirus app has a 100% detection rate, including ClamXav. That's one more reason not to put your faith in an antivirus app to protect you, but rely instead on responsible computing to avoid malware.
  24. macrumors 6502a


    Nobody can be 100% reliant on "resonspible computing" either, hence the need to scan at times.
  25. macrumors 601

    OS X has a build-in malware scanner. I have no idea how it compares to ClamXav, but I would guess that they protect agains the same threats.

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