Virus or trojan

Start by uninstalling your anti virus app. It is not needed and may be causing problems like false alerts.

Yes uninstall it.

It's up to you. I'll step aside then.

Effective defenses against malware and other threats

Phony "tech support" / "ransomware" popups and web pages

No need to remove ClamX. Installed or not, it is unrelated to this issue. Since it's happening from any connection to the Internet, it might be your ISP DNS server (Internet Service Provider DNS) which is compromised and permitting these fake redirects.

In System Preferences>Network>Advanced>DNS tab (that's where it is on my Mountain Lion or Mavericks, but might appear somewhat differently on yours), see if entering these numbers, which will give you OpenDNS (free service), stops these messages.

Remove the current numbers (by selecting them and then probably with a minus - button) and replace them with

208.67.222.222

208.67.220.220

To check that it's working, go to

https://www.opendns.com/welcome/

If this doesn't solve the problem, it might be your router which has been hacked.

http://www.thesafemac.com/how-to-manage-a-hacked-wireless-router/

Strictly speaking I don't think it's "malware," (so disregard the name of the link below) but if you need further help with this go to and register here.

https://forums.malwarebytes.org/index.php?/forum/165-malware-removal-help-for-ma c/

If you decide to go there, you should probably give a link to this thread.

Virus or trojan

BobTheFisherman wrote:

Start by uninstalling your anti virus app. It is not needed and may be causing problems like false alerts.

ClamXav couldn't possibly cause such a problem. Perhaps you should become familiar with it before making such a recommendation. There is no reason to have the OP uninstall it.

From the menu bar, please select

 ▹ System Preferences... ▹ Network ▹ Advanced... ▹ DNS

Under DNS Servers you should have one or more numerical addresses, such as “192.168.1.1” or “10.0.0.1”. What are those addresses?

MadMacs0 wrote:

BobTheFisherman wrote:

Start by uninstalling your anti virus app. It is not needed and may be causing problems like false alerts.

ClamXav couldn't possibly cause such a problem. Perhaps you should become familiar with it before making such a recommendation. There is no reason to have the OP uninstall it.

Maybe ClamXav is not the cause of this specific problem but it may be contributing to this or other issues. Tell us what specific virus it is protecting the OP from so that we can all rush to get an anti virus program installed if indeed it is protected the OP and potentially would prevent the same virus from infecting our computers. ClamXav is doing the OP no good. Perhaps you should become more familiar with the utility of anti virus programs running on a Mac.

Besides being knowledgeable about Mac security issues in general, when it comes to ClamXav, MadMacs0 knows what he's talking about; he does support for ClamXav on its forums.

Besides that, as far as I can tell, this is not a virus or any form of malware, and those alerts are not false. They are genuine messages likely produced in either of the two ways I gave above.

Maybe ClamXav is not the cause of this specific problem but it may be contributing to this or other issues. Tell us what specific virus it is protecting the OP from so that we can all rush to get an anti virus program installed if indeed it is protected the OP and potentially would prevent the same virus from infecting our computers. ClamXav is doing the OP no good. Perhaps you should become more familiar with the utility of anti virus programs running on a Mac.

And as far as I can tell, lacking any genuine first hand information, you are basically just repeating things you have heard about A-V programs in general from others here at ASC. This goes on a lot here.

<Edited by Host>

...as far as I can tell, this is not a virus or any form of malware....

Qualification: minuscule chance it could be the reappearance as some form of

https://www.f-secure.com/v-descs/trojan_osx_dnschanger.shtml

Otherwise, it's long gone.

BobTheFisherman wrote:

Tell us what specific virus it is protecting the OP from so that we can all rush to get an anti virus program installed if indeed it is protected the OP and potentially would prevent the same virus from infecting our computers. ClamXav is doing the OP no good.

That would be off-topic here and note that I never make recommendation as to whether a particular user needs A-V software as it's a personal decision that they need to make for themselves after educating themselves on the current threat to OS X and the impact of using A-V software in general and a specific brand. I simply said it was not the cause of the OP's problem.

Perhaps you should become more familiar with the utility of anti virus programs running on a Mac.

I'm very familiar as I have tested dozens such utilities over twenty years as part of my job.

WZZZ wrote:

Qualification: minuscule chance it could be the reappearance as some form of

https://www.f-secure.com/v-descs/trojan_osx_dnschanger.shtml

Most of what we see in this area today come from hacked routers.

BobTheFisherman wrote:

Maybe ClamXav is not the cause of this specific problem but it may be contributing to this or other issues. Tell us what specific virus it is protecting the OP from so that we can all rush to get an anti virus program installed

Anti-malware apps seem to be getting a rather unfair rap here lately. I fear I may be at least partially to blame, as I've often commented on how bad most Mac anti-malware software is. However, it's very important to understand that it's not all equal. ClamXav, in particular, has never, in my experience, caused any problems for anyone. It's quite well-behaved. As with any piece of software, I'm sure that you could find someone who says ClamXav wrecked their system or something similar... but it's important to keep in mind that without a statistically-significant number of reports, such stories are outliers, and probably dependent on some other factor, like a failing hard drive or corrupt system.

As for what it is protecting people from, I feel that many experienced Mac people downplay the threats average users face today. Admittedly, there's very little actual malware in the Mac world, but there is a plague of adware and PUPs (Potentially Unwanted Programs) out there right now. Mac users are getting infected with this crap at an unprecedented, epidemic level, far worse than anything else I've seen in my 32 years as a Mac user and 10 years on these forums.

If someone wishes to run a program like ClamXav that has the capability of preventing at least some of these infections, they should be allowed to. On the other hand, if they install some awful piece of junk like Norton or McAfee, a warning would be reasonable. Just please make sure that you know which are decent and which are not, either through personal experience or by talking to multiple people with personal experience. Don't paint all anti-malware with the same brush.

And now I've quite thoroughly broken my boycotting of these forums except for to helping people with my software, which I didn't mention at all. But I felt that Mark Allan, developer of ClamXav, deserved defending here. Now to return to my self-imposed exile from this place...