Occasionally, someone asks whether there is a decent virus scanner available for iOS. In this post, I will touch on iOS, macOS and Windows and give some hopefully useful advice for each OS. I know nothing about Linux, but I'm led to believe that there are no viruses in the wild for it. Perhaps someone who uses it can confirm or correct this?
iOS
Taking iOS first, there are NO viruses for iOS, so there is no point in looking for a virus scanner. The best advice is to keep iOS up to date, especially when updates address security issues.
macOS
The same is true of macOS, although the potential exists for them. If a virus ever were to make it into the Mac world, you would certainly hear about it, on this and other forums. So, there is no need to install a virus scanner on a Mac computer. All it will do is slow your Mac down, and likely punctuate your usage with popup messages imploring you to upgrade to a more expensive version.
Windows
Windows, of course, is where virus scanners are invaluable. The above advice still applies. Updating Windows to the latest version is important and will help to guard against malicious code. I won't give advice as to which virus scanner you should use. There are many of them and it really comes down to personal preference. Just don't run two, because they will see each other as a virus, with unpredictable behaviour as a result. It is no fault of Microsoft that viruses are so prevalent. Those who write them simply want the biggest bang for their buck, and Windows supplies it.
Adobe Flash
Personally, I won't install this piece of junk. It is probably responsible for more malware introduction than any other piece of code. However, if you absolutely cannot be without it, set it up to update automatically because exploits for it are continually being found and patched.
What to install
So that covers what you should not install. What about security software that you should install? As far as iOS goes, the answer is simple. None. Exploits on iOS device rely almost entirely on social engineering, and usually appear in the form of a browser hijack. There are two very useful apps for macOS which I recommend. The first is a very powerful tool called OnyX, which is available from http://www.titanium.free.fr/onyx.html. It is OS specific, so make sure you download and install only the version for your OS. Unless you know what you are doing, run only the Automation option, and don't change any defaults. The second is Malwarebytes from https://www.malwarebytes.com/antimalware/mac/. This will hunt down and destroy any malware that manages to make it onto your Mac. Download Mac software only from the Mac App Store or the developers own website. Aggregator sites tend to offer software with their own installer which can introduce malware and change browser settings. There is a plethora of Windows security software, but since I'm hopelessly out of date as far as Windows is concerned, I won't make any suggestions as to which are useful and which are not. Windows forums are the best place to find up to date information.
Browser Hijack
Browser hijacks usually come in the form of a window appearing in the middle of the screen with no apparent way to shut it down. The window usually contains a warning that your system has been compromised and that you should call the supplied telephone number for advice. There may also be a warning that closing the browser session will result in damage to your system and loss of data.
Whatever you do, do not call the number. Disconnect your device from the Internet, close your browser, clear history and cookies, then reconnect to the Internet. When you restart your browser everything should be back to normal.
Social Engineering
These exploits attempt to catch you unawares and offer your passwords and bank information to someone who should not have them. Fake websites, phone calls and text messages purporting to be from government agencies, etc. Scammers have nothing better to do that figure out ways of separating you from your cash. If you suspect that you are the intended victim of such a scam, you are halfway to beating it. Don't give information to anyone until they are verified. If you don't suspect a website, phone call or text message, learn the value of questioning them. For example, if you receive a message that you are being investigated for tax fraud, ask the "officer" to call you back, but don't give your phone number. Chances are, they dialled your number at random and will simply go on to their next potential target. If they are legitimate, they will have your number, RIGHT? While you are waiting for the call, contact your accountant and let him know. He will probably have up to date information on the current scams.
iOS
Taking iOS first, there are NO viruses for iOS, so there is no point in looking for a virus scanner. The best advice is to keep iOS up to date, especially when updates address security issues.
macOS
The same is true of macOS, although the potential exists for them. If a virus ever were to make it into the Mac world, you would certainly hear about it, on this and other forums. So, there is no need to install a virus scanner on a Mac computer. All it will do is slow your Mac down, and likely punctuate your usage with popup messages imploring you to upgrade to a more expensive version.
Windows
Windows, of course, is where virus scanners are invaluable. The above advice still applies. Updating Windows to the latest version is important and will help to guard against malicious code. I won't give advice as to which virus scanner you should use. There are many of them and it really comes down to personal preference. Just don't run two, because they will see each other as a virus, with unpredictable behaviour as a result. It is no fault of Microsoft that viruses are so prevalent. Those who write them simply want the biggest bang for their buck, and Windows supplies it.
Adobe Flash
Personally, I won't install this piece of junk. It is probably responsible for more malware introduction than any other piece of code. However, if you absolutely cannot be without it, set it up to update automatically because exploits for it are continually being found and patched.
What to install
So that covers what you should not install. What about security software that you should install? As far as iOS goes, the answer is simple. None. Exploits on iOS device rely almost entirely on social engineering, and usually appear in the form of a browser hijack. There are two very useful apps for macOS which I recommend. The first is a very powerful tool called OnyX, which is available from http://www.titanium.free.fr/onyx.html. It is OS specific, so make sure you download and install only the version for your OS. Unless you know what you are doing, run only the Automation option, and don't change any defaults. The second is Malwarebytes from https://www.malwarebytes.com/antimalware/mac/. This will hunt down and destroy any malware that manages to make it onto your Mac. Download Mac software only from the Mac App Store or the developers own website. Aggregator sites tend to offer software with their own installer which can introduce malware and change browser settings. There is a plethora of Windows security software, but since I'm hopelessly out of date as far as Windows is concerned, I won't make any suggestions as to which are useful and which are not. Windows forums are the best place to find up to date information.
Browser Hijack
Browser hijacks usually come in the form of a window appearing in the middle of the screen with no apparent way to shut it down. The window usually contains a warning that your system has been compromised and that you should call the supplied telephone number for advice. There may also be a warning that closing the browser session will result in damage to your system and loss of data.
Whatever you do, do not call the number. Disconnect your device from the Internet, close your browser, clear history and cookies, then reconnect to the Internet. When you restart your browser everything should be back to normal.
Social Engineering
These exploits attempt to catch you unawares and offer your passwords and bank information to someone who should not have them. Fake websites, phone calls and text messages purporting to be from government agencies, etc. Scammers have nothing better to do that figure out ways of separating you from your cash. If you suspect that you are the intended victim of such a scam, you are halfway to beating it. Don't give information to anyone until they are verified. If you don't suspect a website, phone call or text message, learn the value of questioning them. For example, if you receive a message that you are being investigated for tax fraud, ask the "officer" to call you back, but don't give your phone number. Chances are, they dialled your number at random and will simply go on to their next potential target. If they are legitimate, they will have your number, RIGHT? While you are waiting for the call, contact your accountant and let him know. He will probably have up to date information on the current scams.
