Remove "weknow.ac" Malware in Chrome?

iMac (Retina 5K, 27-inch, Late 2015), 3.3 GHz Intel Core i5, 16 GB 1867 MHz DDR3, 1.7 TB free — Running High Sierra 10.13.6 (17G65). For a variety of reasons, Chrome is my default browser, and Google is my default search engine and homepage. While browsing with Chrome two days ago, I made the idiotic mistake of clicking on a Flash download popup and immediately noticed signs of infection by this malware. The main only noticeable effect is that my homepage, tab option, and search engine in the Chrome browser now default to this alien "weknow.ac" search engine, which produces results very different from Google's. I've tried three long phone troubleshooting sessions with Apple Help, including downloading and scanning with Malwarebytes, which read my computer as "clean." Also pursued other remedial steps I've seen suggested in other websites. (Although there are only a few that deal specifically with Chrome on Mac.) Uninstalled Chrome application, including trashing all its support folders from Library. However, the bug still keeps coming back. The "good" news is that Safari (so far) shows no sign of the infestation — so I'm using that as my only browser. However, I don't want my (still relatively new) iMac to go through the rest of its life with this alien entity ticking away in its innards. Can anyone here recommend a more permanent solution to my problem? Is there a third-party malware removal product that's both effective and trustworthy? Thanks in advance for any help.

iMac

Posted on Aug 15, 2018 6:51 AM

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Posted on Sep 20, 2018 6:37 AM

I was finally able to fix this for chrome after having no luck with anything posted here. This is what I discovered:


"weknow.ac" changes a group of Chrome policies so as to set a new default homepage, new tab behavior, etc. You can see your current Chrome policies by typing chrome://policy/ into your URL bar. If you're infected, it should be very obvious as the half-dozen or so policies changed by weknow will be displayed.


All I had to do then was use the command line to delete / modify the affected policies:


defaults write com.google.Chrome HomepageIsNewTabPage -bool false

defaults write com.google.Chrome NewTabPageLocation -string "https://www.google.com/"

defaults write com.google.Chrome HomepageLocation -string "https://www.google.com/"

defaults delete com.google.Chrome DefaultSearchProviderSearchURL

defaults delete com.google.Chrome DefaultSearchProviderNewTabURL

defaults delete com.google.Chrome DefaultSearchProviderName


The changes will not take effect until you restart Chrome.


I recommend following some of the other pieces of advice in this thread, ie definitely do a malware scan too.

310 replies

Feb 27, 2019 6:52 PM in response to Skanson

Thank you!!! It appears to have worked. I wasn't able to figure out how to change my terminal from bash to c-shell, but figured I would try enter your command lines anyway, one at a time, and it seems to have worked beautifully. I went back and checked the chrome policy after restarting chrome and it looked a lot different than when "weknow.ac" was in control.

THANK YOU

Mar 3, 2019 2:23 PM in response to Reuben_Hood

Thank You!! The "weknow..." virus affected my wife's computer (Chrome). Has taken us a long time to find a solution. However, your magic worked! I don't know how you figured this out, but you did. You are fabulous. Also, considering how many people have gotten infected with this, it is surprising that Apple has not created a solution. (We used Apple support and they were, in this case, not able to fix the problem.)


Now the big question: how did you figure this out? (Rhetorical.)

Mar 4, 2019 2:17 PM in response to Skanson

THANK YOU!!! I had been able to fix everything except for opening a new tab in Chrome, and I called Apple four times (hoping to get anyone who could help - but no luck) to no avail.


For those, like me, who had no idea how to open "Terminal", it is in the Applications folder under "Utilities."


There was already some text in there, but after the existing "$" I copied each line (the entire line, starting with defaults), pasted, and hit return. I repeated all six lines. And it worked!


Thanks you!!!

Mar 4, 2019 4:14 PM in response to Reuben_Hood

Can someone tell me (in simple terms, please) what I've done wrong?


I've read the entire thread, found where the Terminal is, and copied and pasted several times, but despite quitting Chrome after each attempt, I still get that "we know/Search" in Chrome.


If you check out my Terminal screen below, I'm obviously doing something wrong (or my Mac is really messed up), because after I copy and paste the commands and then hit Enter, it actually says "Defaults have not been changed."


Bruces-iMac:~ brucezwecker$ defaults write com.google.Chrome HomepageIsNewTabPage -bool false


Bruces-iMac:~ brucezwecker$ defaults write com.google.Chrome NewTabPageLocation -string "https://www.google.com/"


Bruces-iMac:~ brucezwecker$ defaults write com.google.Chrome HomepageLocation -string "https://www.google.com/"


Bruces-iMac:~ brucezwecker$ defaults delete com.google.Chrome DefaultSearchProviderSearchURL


2019-03-04 19:04:28.141 defaults[2913:163766] 


Domain (com.google.Chrome) not found.


Defaults have not been changed.


Bruces-iMac:~ brucezwecker$ defaults delete com.google.Chrome DefaultSearchProviderNewTabURL


2019-03-04 19:04:54.120 defaults[2924:165760] 


Domain (com.google.Chrome) not found.


Defaults have not been changed.


Bruces-iMac:~ brucezwecker$ defaults delete com.google.Chrome DefaultSearchProviderName


2019-03-04 19:05:09.087 defaults[2925:167038] 


Domain (com.google.Chrome) not found.


Defaults have not been changed.


Bruces-iMac:~ brucezwecker$ 


Bruces-iMac:~ brucezwecker$ 


Bruces-iMac:~ brucezwecker$ 

Mar 6, 2019 1:46 PM in response to Skanson

Hey! Have had the We Know malware on my laptop for quite while now and havent had any luck in removing it. When i try to enter the policies or 'commands' into Terminal it says 'command not found'. Can anybody help please? Maybe i'm not copying and pasting the right info? could someone help me out please - what exactly need to be copied and pasted?

Mar 7, 2019 11:35 AM in response to Skanson

Your advice worked for me sort of.

While searching for solution I brought up duckduckgo and which worked great but not in the url. Every new tab opened in weknow, for convenience I added the duckduckgo extension.

I followed your directions to change Chrome polices in the terminal. The first time I stopped after the 3rd or 4th line. I spent several hours "cleaning up" the library with no success so tried your method again. That time everything seemed to work great!

Each tab opened to the google homepage, searches in search bar or URL showed no sign of weknow.

But duckduckgo was now the default search engine. I went to change that and found weknow was still there!

I uninstalled Chrome and moved to Safari (which I had earlier managed to free from weknow)

Next morning I reinstalled Chrome and weknow was in every page and tab.

I opened up the terminal to change the policies after the 4th line - “Domain (com.google.Chrome) not found. Defaults have not been changed”

I started removing apps and deleting files (malware searches come up clean).

I restarted & opened Chrome - Now I can search Google in search bar and weknow is still in the URL.

1st 3 lines are reflected in the policies, but no defaults shown in policy. I am going to try again, I guess starting with line 4.

....

Because weknow is only showing in Chrome now (even after un&re install) is the malware hiding in some file or app in a Chrome specific path?

Mar 13, 2019 3:55 AM in response to Skanson

Thanks a lot Skanson. It's been months that i have been struggling with this.

This solved my problem in an instant.


Just one suggestion - I'm a Mac newbie. So "Use the command line" part confused me a bit. I had to search around and then take a wild guess that you meant Terminal app. I was looking for a command prompt option in my Google Chrome app. (sorry, like i said, newbie!)


It will help people like me if you just mentioned Terminal before what the policies to be changed.


Rest of the answer was bang on. Thanks so much!


Mar 15, 2019 9:19 AM in response to mry50

Hi - I open the finder go to applications, along with all my apps is the utilities folder and in there I can open the terminal.

Weknow can be a challenge to remove in Chrome.

Even after following the instructions to change Chrome policies I uninstalled Chrome completely - then reinstalled it!!!

Keep us posted. I learned a lot trying to get rid of this little monster.



Mar 26, 2019 6:49 AM in response to Skanson

hello.


i did exactly what you recommended after seeing the same thing in another website.

it worked fine. weknow was gone, and i haven't seen that new tab page since.

HOWEVER,

now, when i open a new tab, i simply get an about:blank screen, rather than the normal chrome new tab :/ (see below)


im pretty sure this is due to the delete statements, but im not sure. is there any way i can set it back? i will try using the "write" commands on this later and see if it works but i dont know. please help me out here

Apr 16, 2019 6:46 AM in response to Skanson

I'm not quite sure what search you are referencing. On the screen there is a box with the words "filter policy by name". I typed terminal there and got the response, no policy. At the very top right on my Mac, next to the time is a search icon. I typed terminal there, and got a listing of"possible hits", such as documents, other, PDF documents developer, and show in finder. I see I have chrome policies that have been affected. I feel like I'm so close, but not understanding terminal application. Thank you for any help you can give me!!!


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Remove "weknow.ac" Malware in Chrome?

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