I want to edit the hosts file to block sites that are regarded as undesirable or to block ads.After assigning the loopback IP to an URL that I want to block.
If I go to Firewall\Blocked Zone\Advanced and check Lock Hosts file.Will this prevent from been hijack from malware.

ZoneAlarm Security Suite version:7.0.483.000
TrueVector version:7.0.483.000
Driver version:7.0.483.000
Anti-virus engine version:3
Anti-virus SDK version:
Anti-virus signature DAT file version:966439226
Anti-spyware engine version:
Anti-spyware signature DAT file version:01.200812.5075
AntiSpam version: