Chost trojan – Websites not opening

Posted by Abhishek in virus problems 

7

Jun

Trouble:

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.


Fix:

 

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

C:\WINDOWS\system32\drivers\etc

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

127.0.0.1   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.

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Author + Admin: Abhishek Bhatnagar
Hi, I am a Software Engineer by profession and blogger by passion, I write about computer tips and tricks and solutions for computer problems. You can connect with me at twitter or know more about me on www.abhishekbhatnagar.com.

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6 Users Commented In This Post

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mygif
ASM says, June 23rd, 2008   

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.

bye

mygif
ASM says, June 24th, 2008   

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

any other ideas?

mygif
Rick Bowman says, September 10th, 2008   

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 eBay.com and not eBay.ca and some other websites – when I looked in her Hosts file, it had a bunch of Domain names referenced to 127.0.0.1 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!!!!

mygif
Gmail Does Not Open On My Computer - TroubleFixers - All about fixing computer troubles says, September 18th, 2008   

[...] friend of mine called me up saying that Gmail is not opening on her computer. I asked her to check the hosts file , she did the same but did not find anything wrong there. I asked her to clear the cookies and try [...]

mygif
Zard says, April 4th, 2009   

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.

mygif
Ask TroubleFixers – Solutions To Computer Problems – #13 says, July 27th, 2009   

[...] 1. A particular website does not open on my computer [...]

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