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AD.DOUBLECLICK.NET ???

Every time I try to log into Youtube or GMAIL I get this response in the picture displayed.


"Safari can't verify the identity of the website "ad.doubleclick.net"User uploaded file

iMac (Retina 5K, 27-inch, Late 2014), OS X Yosemite (10.10.1)

Posted on Jan 27, 2015 7:45 PM

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28 replies

Jan 27, 2015 8:23 PM in response to gmobriseno

That sounds like you have some redirect hijack malware.

You should check here, http://www.thesafemac.com/arg-identification/

And here, Remove unwanted adware that displays pop-up ads and graphics on your Mac - Apple Support

to see if you have some adware installed, and how to remove.


While ad.doubleclick.net is a semi-legit service, it shouldn't have a bad certificate.

Jan 27, 2015 9:14 PM in response to gmobriseno

You, or someone using your computer, may have hacked the system to redirect queries to certain servers. The file modified is /etc/hosts.

The easiest way to fix the hosts file is to restore it from a backup that predates the modification, or to copy the unmodified file from another Mac. If you can't do that, then do as below.

Back up all data before proceeding.

If you have more than one user account, you must be logged in as an administrator.

Triple-click anywhere in the line below on this page to select it:

open -e /etc/hosts

Copy the selected text to the Clipboard by pressing the key combination command-C.

Launch the built-in Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Paste into the Terminal window by pressing command-V. I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting. A TextEdit window should open. At the top of the window, you should see this:

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
##
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost

Below that, you may see some other lines. The first 10 lines should be exactly as above, apart from differences in the blank space within lines. Otherwise you can't use this procedure—STOP and ask for guidance.

If the contents of the TextEdit window are as described, close it, then enter the following command in the Terminal window in the same way as before (by copy and paste):

sudo sed -i~ '11,$d' /etc/hosts

This time you'll be prompted for your login password, which won't be displayed when you type it. Type carefully and then press return. If you don’t have a login password, you’ll need to set one before you can run the command. You may get a one-time warning to be careful. Confirm. Quit Terminal.

If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator. Log in as one and start over.

That will fix the hosts file. There is now a copy of the old hosts file with the name "hosts~" in the same folder as "hosts". You can delete the copy if you wish. Don't delete the file named "hosts".

Dec 8, 2015 4:38 PM in response to tripplechipnick

Help with adding the line to the file? (I'd be curious around how the line went missing, as that implies either somebody was editing the file locally, or something installed intentionally or otherwise has altered the file.)


As for your question, first ensure you have a complete and current system backup — that Time Machine is configured and running, and that Time Machine has completed a backup recently. Then download TextWrangler for your version — that's a free GUI-based text editor that will maintain the file format of this file correctly — and use File > Open file by name option and specify the file /etc/hosts, and add the line, unlocking the file when prompted.


The ad.doubleclick.com site referenced in the thread you're replying to here is presently throwing a different certificate error today — not the same error that apparently started off this thread. They apparently have something else going on, or they are trying to collect identity certificates from folks. Cancel it, when it pops up.


User uploaded file

Dec 8, 2015 7:05 PM in response to Tevinarnott

Tevinarnott wrote:


What do I do if I accidentally gave them my identity certificate?


Nothing you can do, short of re-issuing whichever identity certificate was provided to them. How that's done depends on the certificate.


Given a public certificate that's been provided, they can't do much more than use it to track you better. Doubleclick is a subsidiary of Google, so they already seek to collect all sorts of information on everybody anyway.

AD.DOUBLECLICK.NET ???

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