Your Original HOSTS file was infected and it was replaced by this file containing only clean default entries.

Issue:

When opening the hosts file on a Windows device, it only shows the following text: 

# 
# This is a HOSTS file created during malware removal. 
#
# Your original HOSTS file was infected and it was replaced 
# by this file containing only clean default entries. 
# The original HOSTS file may be restored from the product's
# quarantine feature.
#
127.0.0.1    localhost
::1            localhost

Resolution:

The Protect the Hosts file security feature monitors if there have been any changes made to the hosts file in a Windows system. If the feature detects changes, it will alert of a redirected hosts file and replace it with a hosts file with the content shown above. 

If a hosts file has been modified before the installation of Business Suite Client Security, Business Suite Server Security or Elements Agent (Elements Endpoint Protection), the modified hosts file will be detected during the first system scan.

If the hosts file is modified during a time when the Protect the hosts file feature has been disabled, the modified hosts file will be detected when the feature is turned back on. 

Follow these steps to turn off the Protect the hosts file feature:

For Business Suite products:

1. Log in to Policy Manager Console
2. Select the policy domain or host from the Domain Tree
3. Go to the Settings tab 
4. Navigate to Windows > Real-Time Scanning > Real-Time Scanning
5. Scroll down to the Actions on riskware/spyware detection (workstations) section
6. Disable the Protect the "Hosts" file setting
7. Distribute the policy (Ctrl + D)

For Elements Endpoint Protection products: 

1. Log in to the Elements Endpoint Protection portal
2. Go to the Security configurations > Profiles page
3. Click on the profile that is in use on the devices
4. Go to the Real-time scanning settings page
5. Scroll down to the File scanning section
6. Disable Protect Hosts file 
7. Click Save profile

We do not suggest to exclude this file from scanning, but we do suggest to keep a backup file of the original or manually changed host by user itself.