Virus is blocking Internet access, how to eliminate it?

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Internet access is blocked due to malware infection, how to eliminate it?

This tutorial describes how to re-establish Internet access if blocked by malware. Some malware variants modify Internet browser settings by adding a Proxy Server. In these cases, you will be unable to visit any websites, and thus not able to download the required software to eliminate the security infections. Other types of malware change the computer's DNS settings or add various entries to your operating system's Hosts file. By altering these settings, computer viruses can cause redirect issues or completely block the Internet connection. If you cannot access the Internet, and suspect that this is caused by a virus infection, check the settings below.

If you cannot access the Internet due to a malware infection, first try booting your computer in Safe Mode with Networking. You can find out how to do this in our 'how to remove spyware?' section. If you are still unable to access the Internet, use these instructions:

Check Proxy Server settings in Internet Explorer:

1. Open Internet Explorer. At the top right corner of the main window, click the 'wrench' icon. In the opened drop down menu, choose 'Internet Options'.

Internet Explorer Internet settings

2. In the opened window, select the 'Connections' tab.

Internet options connections tab

3. In the 'Connections' tab, click the 'LAN settings' button.

Internet Explorer lan settings

4. In the 'Lan settings' window, ensure that the 'Use a proxy server for your LAN' option is not checked (otherwise, uncheck it and click 'OK').

lan settings proxy server

Check your computer's DNS settings:

1. Click the 'Windows logo' (Start button).

click start

2. In the opened menu, select 'Control Panel'.

control panel

3. In the opened window, click 'Network and Internet'.

network and Internet

4. In the opened window, click 'View network status and stats'.

view network status and tasks

5. Click 'Local Area Connection'.

local area connection

6. In the opened window, click the 'Properties' button.

local area connection properties

7. In the 'Properties' window, select 'Internet Protocol (TCP/IP)' and click the 'Properties' button.

Internet protocol settings

8. In the opened window, check if 'Obtain DNS server address automatically' is checked.

obtain DNS server automatically

Check your operating system's Hosts file.

Locate your Hosts file. You should find it at %systemroot% \system32\drivers\etc (commonly, it will be c:\windows\system32\drivers\etc). Open the Hosts file with Notepad and verify that no unusual values have been added to it.

These are the default values, and yours should be the same:

Default Windows XP Hosts File:

# Copyright (c) 1993-1999 Microsoft Corp.

#

# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.

#

# This file contains the mappings of IP addresses to host names. Each

# entry should be kept on an individual line. The IP address should

# be placed in the first column followed by the corresponding host name.

# The IP address and the host name should be separated by at least one

# space.

#

# Additionally, comments (such as these) may be inserted on individual

# lines or following the machine name denoted by a '#' symbol.

#

127.0.0.1 localhost

Default Windows Vista Hosts File:

# Copyright (c) 1993-2006 Microsoft Corp.

#

# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.

#

# This file contains the mappings of IP addresses to host names. Each

# entry should be kept on an individual line. The IP address should

# be placed in the first column followed by the corresponding host name.

# The IP address and the host name should be separated by at least one

# space.

#

# Additionally, comments (such as these) may be inserted on individual

# lines or following the machine name denoted by a '#' symbol.

#

127.0.0.1 localhost

::1 localhost

Default Windows 7 Hosts File:

# Copyright (c) 1993-2006 Microsoft Corp.

#

# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.

#

# This file contains the mappings of IP addresses to host names. Each

# entry should be kept on an individual line. The IP address should

# be placed in the first column followed by the corresponding host name.

# The IP address and the host name should be separated by at least one

# space.

#

# Additionally, comments (such as these) may be inserted on individual

# lines or following the machine name denoted by a '#' symbol.

#

# localhost name resolution is handle within DNS itself.

# 127.0.0.1 localhost

# ::1 localhost

After checking and correcting these settings, your Internet connection should be back to normal. If you are dealing with malware infections, we recommend downloading anti-spyware software from our Top Anti-Spyware programs list and running a full system scan.

Haig

Check this video I made very detailed https://youtu.be/bsvD9RsZEGU

Haig

For those that can not open host file with notepad are save changes you need to right click the host file go into properties then change file permissionsize make sure you have full control of the file then it should allow you to edit it and save changes

Trio Kaim

Natalie, I got the same thing. But went to Microsoft's site, and apparently those characters belong there. I was puzzled for a minute as well.

Natalie Spasic

Ok So I found some extra text in my host file:

# For example:

# 102.54.94.97 rhino(dot)acme(dot)com # source server

# 38.25.63.10 x(dot)acme(dot)com # x client host

Now I want to delete this text but my computer will not let me open it??? I was able to browse and open with notepad. But Is it ok for me to save it as a notepad file and put it back in the folder?
I am logged in as an admisitrator

Now I also need to mention that I have run these programs: ( Malware Bytes, Spy Hunter, AVG, Hitmanpro, Adwcleaner, CC Cleaner) Malware Bytes caught the Pum files and trojan horse and it quarantined them but the next day around the same time, I had the same problem again. I noticed that is made the google chrome icon disappear to a File like picture. None of my internet browsers worked. Only after Every day I had to quarantine this virus, I restarted the computer it it stays gone for 24 hours.

Viruses/Malware IT CAUGHT:

Pum.Bad.Proxy (Registry)
Trogan.Agent (File)

Conrad Hubble II

i cant find the host file. What is it?

Travis

I tried posting yesterday but it never made it... I have tried all of the steps listed, multiple different malware and virus removers, and other similar websites with slightly different ideas for removing this stuff. I've even tried safe mode with networking and run all of the same things. I know it is not the network itself as that was the first thing I tried. I have had ZERO luck in getting rid of it still. Anyone have any ideas? Please help.

Travis

I have tried every step listed here including running full system scans with AVG, Microsoft Essentials, Malwarebytes and then some from other similar sites with slight variations to remove it, but no luck for me. I still have a major block not letting me connect my desktop and it is surely not the internet connection itself. The old unused laptop has surely come in handy, but I need my desktop back! Anyone have any other ideas? I'm just about to chuck the machine and salvage the HDD. I have spent over 9 hours trying everything

Catherine

Hi, after following your advice and opening it after logging in as an administrator, the hosts file doesn't show up anymore? After system 32-drive-etc it says no items match your search so I am unable to change anything/ save the file. Please help :(

Hobo

Thank you you changed my life!