If I understand correctly, you are trying to install Office Offline from the Chrome Web Store, but you get the error "NETWORK_FAILED".  You are also saying, separately, that neither Chrome Cleanup Tool nor Mayware Bytes found any malware on your system.  Is that correct?

Please create a new user profile and try installing the extension using that profile.  If that does not work, please disable your firewall and antivirus temporarily, then try installing the extension.  (Do not forget to turn your firewall and antivirus back on you after this.)  Please report back here whether you succeeded or not.  Thank you.

Thanks, I finally found the solution, just delete the line with google in hosts file
C:\Windows\System32\drivers\etc

Thank you for providing more feedback. Adding requester "bnc@chromium.org" for another review and adding "Needs-Review" label for tracking.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Malware Byte found the Malware and delete it but until i modify the host file download extensions doesn't work

C:\Windows\System32\drivers\etc\hosts has known IP addresses that your system will use instead of resolving them with a DNS.  I do not think any google hostname belongs to this file.  This might have been put there by the malware to hijack connections to google, and this is exactly why you were not able to download the extension.  I am glad you found a way to clean up this malware, and eventually managed to install the extension.

Exact, Malware Bytes remove the malware, but we need to clean the host file manually to load extension, hope this post help other pepole. Regards