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Whenever I open IE8, or a new tab in IE8, AVG will prompt a warning about thunder.dll as posing a threat and says that it is a trojan horse.

The file is located at: C:\Windows\SysWOW64\thunder.dll

Is this something I should be worried about? What should I do?

I am using Windows 7 64bit with Internet Explorer 8.

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THUNDER.DLL has been seen to perform the following behavior:

* The Process is packed and/or encrypted using a software packing process
* The Process is polymorphic and can change its structure
* Creation and Registration of a Browser Helper Object in Internet Explorer
* Enables an In Process Object/Server - Common with DLL Injections
* Registers a Dynamic Link Libray (DLL) File
* Registers a Dynamic Link Library File
* Found on infected systems and resists interrogation by security products

Thus, you should use some removal tools .also I think that AVG could be able to remove it.

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I tried to use "Move to Vault" option in AVG and the system hangs. I restart the windows, and open IE8. The next thing is that the warning prompts up again. – user31788 Mar 29 '10 at 1:40
have you tried to remove with removal tools heh ? – Ye Lin Aung Mar 29 '10 at 1:58

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