Q: How to find/get rid of viruses
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Nov 22, 2013 10:54 AMby Linc Davis,Thomas, please stop making up nonsense about what I believe or don't believe. Either you don't know, or you're deliberately misrepresenting my position.
"Icefog" is a trojan. No Mac user who follows safe computing practices is vulnerable to trojans, and anyone who does not follow those practices is vulnerable, with or without Sophos. Neither Sophos nor any other software would have protected the victims of that particular attack from the consequences of their own stupidity while it was in progress. There isn't a shred of evidence that anyone was protected from the attack that way.
I've never said that OS X defenses against malware are "impenetrable;" in fact, I've said the very opposite of that on this site at least a few hundred times, and I'm saying it again now.
You seem to be unable or unwilling to grasp the idea that the defense against a threat must be commensurate with the degree of risk reduction. Even if you choose to believe -- again, without a shred of supporting evidence -- that "Sophos" reduces the real-world risk of malware infection, that reduction is not commensurate with burden of resource wastage and instability that it imposes on the user. It's as if you were going to protect yourself from being hit by a car by only leaving your house in an armored personnel carrier. Yes, that might reduce your risk of being hit by a car, but you can protect yourself almost as well by looking both ways before crossing a busy intersection. That's what a rational person does. He doesn't bog down his computer with crapware that is going to end up costing him far more in lost productivity than it will ever save him, if it saves him anything at all.
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Nov 22, 2013 11:38 AMby thomas_r.,[...] the consequences of their own stupidity [...]
See, that's the issue. You seem to view anyone who gets tricked by something like a trojan as "stupid." That's out of touch with reality, as well as extremely insulting to the people you're trying to instruct.
It is easily possible for people who are not being "stupid" to end up getting fooled. "Safe computing practices" are less well-defined in the presence of things like legit sites that have been hacked, signed malware and vulnerabilities that allow an innocuous Microsoft Word document to install malware.
What, exactly, would you recommend to keep people who you feel are being "stupid" safe? Do you simply write them off as too "stupid" to help?
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Nov 22, 2013 12:35 PMby Linc Davis,1. This comment applies to malicious software ("malware") that's installed unwittingly by the victim of a network attack. It does not apply to software, such as keystroke loggers, that may be installed deliberately by an intruder who has hands-on access to the victim's computer. That threat is in a different category, and there's no easy way to defend against it. If you have reason to suspect that you're the target of such an attack, you need expert help.If you find this comment too long or too technical, read only sections 5, 6, and 10.OS X now implements three layers of built-in protection specifically against malware, not counting runtime protections such as execute disable, sandboxing, system library randomization, and address space layout randomization that may also guard against other kinds of exploits.
2. All versions of OS X since 10.6.7 have been able to detect known Mac malware in downloaded files, and to block insecure web plugins. This feature is transparent to the user, but internally Apple calls it "XProtect." The malware recognition database is automatically checked for updates once a day; however, you shouldn't rely on it, because the attackers are always at least a day ahead of the defenders.The following caveats apply to XProtect:- It can be bypassed by some third-party networking software, such as BitTorrent clients and Java applets.
- It only applies to software downloaded from the network. Software installed from a CD or other media is not checked.
As new versions of OS X are released, it's not clear whether Apple will indefinitely continue to maintain the XProtect database of older versions such as 10.6. The security of obsolete system versions may eventually be degraded. Security updates to the code of obsolete systems will stop being released at some point, and that may leave them open to other kinds of attack besides malware.3. Starting with OS X 10.7.5, there has been a second layer of built-in malware protection, designated "Gatekeeper" by Apple. By default, applications and Installer packages downloaded from the network will only run if they're digitally signed by a developer with a certificate issued by Apple. Software certified in this way hasn't necessarily been tested by Apple, but you can be reasonably sure that it hasn't been modified by anyone other than the developer. His identity is known to Apple, so he could be held legally responsible if he distributed malware. That may not mean much if the developer lives in a country with a weak legal system (see below.)Gatekeeper doesn't depend on a database of known malware. It has, however, the same limitations as XProtect, and in addition the following:- It can easily be disabled or overridden by the user.
- A malware attacker could get control of a code-signing certificate under false pretenses, or could simply ignore the consequences of distributing codesigned malware.
- An App Store developer could find a way to bypass Apple's oversight, or the oversight could fail due to human error.
For the reasons given above, App Store products, and other applications recognized by Gatekeeper as signed, are safer than others, but they can't be considered absolutely safe. "Sandboxed" applications may prompt for access to private data, such as your contacts, or for access to the network. Think before granting that access. OS X security is based on user input. Never click through any request for authorization without thinking.4. Starting with OS X 10.8.3, a third layer of protection has been added: a "Malware Removal Tool" (MRT). MRT runs automatically in the background when you update the OS. It checks for, and removes, malware that may have evaded the other protections via a Java exploit (see below.) MRT also runs when you install or update the Apple-supplied Java runtime (but not the Oracle runtime.) Like XProtect, MRT is effective against known threats, but not against unknown ones. It notifies you if it finds malware, but otherwise there's no user interface to MRT.5. The built-in security features of OS X reduce the risk of malware attack, but they're not absolute protection. The first and best line of defense is always going to be your own intelligence. With the possible exception of Java exploits, all known malware circulating on the Internet that affects a fully-updated installation of OS X 10.6 or later takes the form of so-called "trojan horses," which can only have an effect if the victim is duped into running them. The threat therefore amounts to a battle of wits between you and the malware attacker. If you're smarter than he thinks you are, you'll win.That means, in practice, that you never use software that comes from an untrustworthy source, or that does something inherently untrustworthy. How do you know what is trustworthy?- Any website that prompts you to install a “codec,” “plug-in,” "player," "extractor," or “certificate” that comes from that same site, or an unknown one, is untrustworthy.
- A web operator who tells you that you have a “virus,” or that anything else is wrong with your computer, or that you have won a prize in a contest you never entered, is trying to commit a crime with you as the victim. (Some reputable websites did legitimately warn visitors who were infected with the "DNSChanger" malware. That exception to this rule no longer applies.)
- Pirated copies or "cracks" of commercial software, no matter where they come from, are unsafe.
- Software of any kind downloaded from a BitTorrent or from a Usenet binary newsgroup is unsafe.
- Software that purports to help you do something that's illegal or that infringes copyright, such as saving streamed audio or video for reuse without permission, is unsafe. All YouTube "downloaders" are in this category, though not all are necessarily harmful.
- Software with a corporate brand, such as Adobe Flash Player, must be downloaded directly from the developer’s website. If it comes from any other source, it's unsafe.
- Even signed applications, no matter what the source, should not be trusted if they do something unexpected, such as asking for permission to access your contacts, your location, or the Internet for no obvious reason.
Fortunately, client-side Java on the Web is obsolete and mostly extinct. Only a few outmoded sites still use it. Try to hasten the process of extinction by avoiding those sites, if you have a choice. Forget about playing games or other non-essential uses of Java.Java is not included in OS X 10.7 and later. Discrete Java installers are distributed by Apple and by Oracle (the developer of Java.) Don't use either one unless you need it. Most people don't. If Java is installed, disable it — not JavaScript — in your browsers.Regardless of version, experience has shown that Java on the Web can't be trusted. If you must use a Java applet for a task on a specific site, enable Java only for that site in Safari. Never enable Java for a public website that carries third-party advertising. Use it only on well-known, login-protected, secure websites without ads. In Safari 6 or later, you'll see a lock icon in the address bar with the abbreviation "https" when visiting a secure site.
Follow the above guidelines, and you’ll be as safe from malware as you can practically be. The rest of this comment concerns what you should not do to protect yourself from malware.
7. Never install any commercial "anti-virus" or "Internet security" products for the Mac, as they all do more harm than good, if they do any good at all. Any database of known threats is always going to be out of date. Most of the danger is from unknown threats. If you need to be able to detect Windows malware in your files, use one of the free anti-virus products in the Mac App Store — nothing else.Why shouldn't you use commercial "anti-virus" products?- Their design is predicated on the nonexistent threat that malware may be injected at any time, anywhere in the file system. Malware is downloaded from the network; it doesn't materialize from nowhere.
- In order to meet that nonexistent threat, the software modifies or duplicates low-level functions of the operating system, which is a waste of resources and a common cause of instability, bugs, and poor performance.
- To recognize malware, the software depends on a database of known threats, which is always at least a day out of date. Most of the real-world danger of malware attack comes from highly targeted "zero-day" exploits that are not yet recognized.
- By modifying the operating system, the software itself may create weaknesses that could be exploited by malware attackers.
8. An anti-malware product from the App Store, such as "ClamXav," doesn't have these drawbacks. That doesn't mean it's entirely safe. It may report email messages that have "phishing" links in the body, or Windows malware in attachments, as infected files, and offer to delete or move them. Doing so will corrupt the Mail database. The messages should be deleted from within the Mail application.An anti-virus app is not needed, and should not be relied upon, for protection against OS X malware. It's useful only for detecting Windows malware. Windows malware can't harm you directly (unless, of course, you use Windows.) Just don't pass it on to anyone else.A Windows malware attachment in email is usually easy to recognize. The file name will often be targeted at people who aren't very bright; for example:♥♥♥♥♥♥♥♥♥♥♥♥♥♥!!!!!!!H0TBABEZ4U!!!!!!!.AVI♥♥♥♥♥♥♥♥♥♥♥♥♥♥.exeAnti-virus software may be able to tell you which particular virus or trojan it is, but do you care? In practice, there's seldom a reason to use the software unless a network administrator requires you to do it.The ClamXav developer won't try to "upsell" you to a paid version of the product. Other developers may do that. Don't be upsold. For one thing, you should not pay to protect Windows users from the consequences of their choice of computing platform. For another, a paid upgrade from a free app will probably have the disadvantages mentioned in section 7.9. It seems to be a common belief that the built-in Application Firewall acts as a barrier to infection, or prevents malware from functioning. It does neither. It blocks inbound connections to certain network services you're running, such as file sharing. It's disabled by default and you should leave it that way if you're behind a router on a private home or office network. Activate it only when you're on an untrusted network, for instance a public Wi-Fi hotspot, where you don't want to provide services. Disable any services you don't use in the Sharing preference pane. All are disabled by default.10. As a Mac user you don't have to live in fear that your computer is going to be infected every time you install an application, read email, or visit a web page. But neither should you have the false idea that you will always be safe, no matter what you do. The greatest harm done by security software is precisely its selling point: it makes people feel safe. They may then feel safe enough to take risks from which the software doesn't protect them. Nothing can lessen the need for safe computing practices. -
Nov 22, 2013 12:47 PMby Linc Davis,It is easily possible for people who are not being "stupid" to end up getting fooled.
I've been a fairly active Internet user for quite a while myself, and somehow I have managed to avoid being "fooled" into installing a trojan. In fact, during some malware outbreaks I actively tried to become infected and was usually unable to do it.
Contrary to what you seem to think, I don't regard other computer users as being so much less intelligent than I am that they can't mitigate the risk in the same way I do. You're the one who apparently thinks people are too stupid to use a computer safely.
