Chost trojan – Websites not opening

by Abhishek Bhatnagar on June 7, 2008



One of our readers Kapil reported that his computer has been infected with chost trojan. Because of this trojan certain web-sites are not opening. This kind of problem can also be caused by trojan.vundo .


Although this is a old known trojan, so your anti-virus software should have virus-definitions to take care of this trojan. But even if the anti-virus software has cleaned the trojan, the chances exist that you will still face problem in opening web-sites.


unable to connect


This is so because this trojan modifies your windows “hosts file” and makes certain web-sites point to a local host. Such web-sites will not load until this host files is corrected.


Let us see how take care of the trojan and fix the hosts file.



To fix the trojan, update your anti-virus software virus-definitions and run a full system scan. To see additional tips on protections against viruses, see this post.



Once you run a scan and clean the computer of the trojan, half-job is done. For rest half, you need to correct the host file. Go to location


and open the host file located at this path with Notepad.

hosts file

Delete all the contents of this file and type the line below   localhost

local host settings

Save and close this file. Restart your computer. Done!

But if you are still facing problem, it can also be because of DNS servers problem, see this link for solution.

If you like this article or this article helped you, you can +1 to recommend this article on google plus.

You can follow us on Twitter or join our Facebook Fan Page. If you have a question to ask us, submit your question at Answers By Trouble Fixers.

Looking for something else? Search here :

{ 19 comments… read them below or add one }

ASM June 23, 2008 at 11:44 pm

Hi rohit,

thanks for the reply. i did open the file in notepad and deleted the contents. however, i am unable to save the file. it says “cannot create the C:\WINDOWS\system32
drivers\etc\hosts file” “Make sure that the path and filename are correct” seems like the extension is not supported. what extension is the file to be saved with?

please let me know.


ASM June 24, 2008 at 12:02 am

i have saved the file as you said and restarted the didnt work.

any other ideas?

Rick Bowman September 10, 2008 at 5:53 pm

Hi – I foud your article while Googling for “Internet Explorer cannot display the webpage”. I didn’t feel that I had the chost trojan but I decided to checkout your posting anyway and am glad I did. For long frustrating time I’ve not been able to access certain websites from my LapTop only. It turns out that TweakMaster changed my Hosts file to add the IPs for Domains I had visted. Unfortunately after the IP address of one of the websites was changed, TweakMaster didn’t or wasn’t able to update the IP address in the Hosts file making it impossible for me to access it. Later, TweakMaster was bugging me too much so I de-installed it – that left my Hosts file full of IP addresses without any update capability. So more sites would eventually be added to the list of non-accessable. Once I remarked out the problem IP/DNS in the Hosts file, I was back in business thanks to you. I imagine there are a lot of DNS acclerator programs out there with the potential of screwing up users’ Hosts files – and not just viruses. On my wife’s desktop, I was shut out of and not and some other websites – when I looked in her Hosts file, it had a bunch of Domain names referenced to which effectively blocked those sites – I’m not sure what program or person did this, but until you made me aware of the Hosts file, I would be blocked forever – you have no idea how much help you have been – thanks thanks thanks!!!!

Zard April 4, 2009 at 7:34 pm

I have the exactly same problem just like ASM.
It says “Make sure that path and file name are correct.”
It won’t let me make changes. Please tell me what to do now.

Charlie December 2, 2009 at 2:23 am


Samantha December 5, 2009 at 1:37 pm

We need more posts like this!

john April 9, 2010 at 1:13 pm

thank u thak u thank u this works like a charm picked a malware and couldnt open any email especially gmail tryed virus checker and spyware removal all done in safe mode but still cant accesss my mail read yr article copyed old host file removed old host file (origanal)to a safe place (my Documents)renamed copyed host file to host opened it deleted everything copyed yr text restarted computer and hey hey it works can now access email

thank u champ

Rohit August 5, 2010 at 11:06 pm

This really works! Thanks :)

Binaya August 17, 2010 at 5:00 pm

Hey I got the Same problems after installing active speed program.. How to recover from it.. I am unable to open yahoo mail and gmail..I unistalled this program enen though the problem is not solved.. What to do??

Vrinda September 23, 2010 at 3:55 pm

I followed the steps you have given til “etc”. But there is no host file in this folder on my PC.

joseph October 3, 2010 at 6:28 pm

orkut and gmail cant open in my system

Govinder Singh October 10, 2010 at 10:19 pm

go to

and open the host file located at this path with Notepad.
change the ip add to
problem solved

Venu October 14, 2010 at 7:09 pm

Yeah, it worked great.
I cleared all the data in the host file and saved it. Later I restarted my laptop and BOOM, it worked, I can access all the websites as usual.

Initially it didn’t allow me to save the changes, but I changed the administartor permissions to READ and WRITE and Applied it. It worked like a charm. KUDOS TO YOU!

Thanks for the great tip.

isbut November 3, 2010 at 10:13 pm

gud dud it worked out

Ben November 4, 2010 at 6:10 am

I had the same problem as Venu, but I changed the permissions and it still does not work. I can only use the Gmail website, and a few random banks. Does anyone have any ideas?

Leave a Comment

Previous post:

Next post:

© TroubleFixers – All about fixing computer troubles2007-2016 . All Rights Reserved.