Host Flash™

Host Flash™ v4.0.0

Lead Author: Lee Hodson

Website: https://host-flash.com

Donate: paypal.me/vr51

This Release: 3rd July 2020

First Written: 18th Oct 2015

First Release: 2nd Nov 2015

Copyright Host Flash™ https://host-flash.com

License: GPL3

Programmer: Lee Hodson <journalxtra.com>, VR51 <vr51.com> Contributor: skeletonkey https://github.com/skeletonkey/

Use of this program is at your own risk

FILE TO DOWNLOAD:

You only need to download the file hostflash.

All the other files in this repository are for reference or emergency only.

TO RUN:

• Ensure the hostflash file is executable:
• Right-click > properties > Executable
• OR
• chmod u+x hostflash
• Run with:
• Command line: bash hostflash or ./hostflash
• OR
• File browser: just click hostflash

Use the Host Flash™ program menu to install Essential Software dependencies needed by Host Flash™. Essential software is installed with the apt package manager. The software is fetched from your distro's own repositories i.e they are safe to install, or should be if you use a reputable dist.

Use Host Flash™ to block computer requests to (and access to) websites (hosts), ad servers, malicious websites and time wasting websites.

Use Host Flash™ to manage the Linux hosts file

Host Flash™ works at the OS level. This means any request from any program or app sent to any flagged external host is blocked.

Host Flash™ does not block requests sent to IP addresses. Use iptables to manage IP address access rules.

Note about changelogs. We only keep the last couple of changelog notes. This helps keep the readme short.

New in 4.0.0

Version 4.0.0 heralds a change in the way HostFlash functions. From the enduser viewpoint there is no change to the way HostFlash is used - it works in the same way as version 3.x. From a developers point of view there will soon be a way to create modular plugins for HostFlash. If you paid attention to that last sentence you will be smiling happy that the future of HostFlash is modular.

• Auto-detection of source host list file type. No need to flag the file type in custom lists. The now obsolete flags were: zip, p7, raw and direct. Currently, errors show when source files are initially processed. These errors can be ignored; they are caused because we try to unzip/unpackage every downloaded file type, which is quicker than mime type tests to findg the right archive program before unzip, untar etc... May as well just go for it instead of messing around.
• New directory structure
  • Permanent Directories ~/hostflash/backups ~/hostflash/DOCS ~/hostflash/logs
  • Temp. Directories. These are deleted when a new hosts file is built (unless DEBUG is set to '1', in which case they are left in place) ~/src/tmp/download ~/src/tmp/unprocessed ~/src/tmp/processed
  • Config Directory restructure ~/.configs/.hostflash ~/.configs/hostflash/.lists # To be used later ~/.configs/hostflash/.menus # To be used later ~/.configs/hostflash/.plugins # To be used later
• Replaced hosts files are now zipped to the backup directory. Preview and Restore options to be added later.
• Hosts file summary info is now written to the history log when a host file is built.
• Function __log now logs three message types: log, hist and debug. The __debug will eventually be rolled into __log.
• Function __log with 'debug' flag causes cURL to log the head fetched with source file downloads to the debug file.

New in 3.2.0

• Fixed legacy bug. The bug affected Host Flash users who had missed a couple years of HF script updates. The bug caused the HF hosts file to not disable when selected to do so through the user menu. Users who discovered HF at version 3.x and above were never affected by this bug.
• Adjusted the way we extract hosts rules from source lists. New method is more direct to point and more efficient. HF now extracts from source files all lines that begin with an IP address. Previous method used a clean-and-merge process.

New in 3.1.9

• Updated hosts file source URLs from HTTP to HTTPS where available.
• Changed some hosts file source URLs to reflect organisational changes in their host websites.
• Added Developer Dan's Ads and Trackers Aggressive hosts list - See https://www.github.developerdan.com/hosts/
• Minor bug fixes.

Features

• Better hosts file management
• Great performance with faster processing time
• More host blacklist repositories to choose from (27 built in, 3 Host Flash community lists and 3 user customizable lists)
• Text mode terminal GUI. Dialog, whiptale and other terminal GUIs were overkill for this app so were removed some time ago.
• Custom settings are stored in $HOME/.config/hostflash/.hf* files (.hfrc, .hfwlrc, .hfwlwrc and .hfblrc, .hfremoved, .debug, and log)
• Update local custom whitelist or blacklist through the GUI
• Update hosts file with local custom rules without rebuilding the whole hosts file
• Apply rule change updates without complete hosts file rebuild
• List management. Easily add new host list repositories from within the Host Flash™ app.
• Local DNS Cache automatically cleared after hosts file installation or update
• Better information about installed HF version to help you recognise when an update is available.
• Better config reset management.
• Use basic Grep regexes in whitelists.
• Hosts removed through whitelist rules are logged to $HOME/.config/hostflash/.hfremoved so you can review and update whitelist rules.
• More to come...

What Host Flash™ Does

Host Flash™ installs a hosts blacklist into your computer. This blacklist consists of bad hosts, undesirable hosts, ad hosts and trackers. All hosts are websites. When installed, the blacklist prevents your computer from accessing content served by the blacklisted web hosts. Host Flash™ is a simple firewall.

Host Flash™ is interactive and configurable

The interactive set-up program lets you control the host file firewall rules installed by Host Flash™ and lets you manage the actions performed by Host Flash.

Host Flash™ compiles and installs a blacklist of malware, adserver, tracker and cryptominer hosts. This prevents your computer making requests to domains (hosts) that could compromise your computer and privacy. You can choose the host lists to download and install.

Host Flash™ can install your hosts file for you and provide an easy way for you to enable, disable and otherwise manage your system hosts file.

Be aware that hosts file redirect rules can be bypassed by use of a VPN such as the one provided by the Opera browser or by a Tor browser.

Host Flash™

• downloads host name / domain name blacklists from any of one or more of over 20 host blacklist repositories
• merges those lists into one large compilation of bad hosts
• adds your customizable bad hosts blacklist into the mix (.hfblrc)
• removes duplicate bad host entries from the compiled bad hosts list
• removes whitelisted hosts from the compiled list (.hfwlrc and .hfwlwrc)
• copies the hosts file that exists when Host Flash™ is first run to /etc/hosts.hf.original
• copies successive hosts file replacements to /etc/hosts.hf.backup
• option to remove previously installed Host Flash™ firewall from the existing hosts file
• retains the hosts file entries that already exist in the original hosts file so that the hosts file created by Host Flash™ does not remove your own custom hosts file edits (provided they are placed above the Host Flash header)
• can be used in web server environments
• the redirect IP address is configurable

Run Host Flash™ regularly to keep your hosts file up-to-date with new bad hosts.

Run Host Flash™ if you need to undo changes made to the hosts file by Host Flash™

Use Host Flash™ to manage your computer's hosts file.

Make sure manual edits to the hosts file are above the content added by Host Flash™ otherwise Host Flash™ will delete them when the rules are updated.

Updates to the hosts file rules that are managed through Host Flash™ will be respected by Host Flash™ in subsequent funs.

Requirements

This program needs curl, sed, zip, unzip and p7zip to be installed in the OS environment. Host Flash™ will display an alert if any of these programs is not installed and will prompt you to install them (see Host Flash™ options).

This software is known to work on Debian Linux systems. It may or may not work on other Unix based systems. It is a BASH program so any system with BASH installed should be fine.

Portability

Host Flash™ will run in many Debian (and probably non Debian) environments like Ubuntu, Kubuntu and Debian. It might work on rooted Android devices, though full BusyBox needs to be installed into Android with a few additional shell scripts (though it is quicker and easier to compile the hosts file on a full Linux machine then transfer the file to Android).

If you want to reuse local Host Flash™ settings in other environments, just move the .hf* files from $HOME to the $HOME of other environments.

How to Use Host Flash™

Download Host Flash™ from GitHub, run the program, follow the on screen prompts to quickly configure the program and install your new hosts file block list. Custom settings automatically saved by Host Flash™ in realtime.

• Download the program from https://github.com/VR51/host-flash/
• You only need to download the file called hostflash
• Run hostflash

Programatically, that is

wget https://github.com/VR51/host-flash/archive/master.zip ; unzip host-flash-master.zip ; cd host-flash-master ; chmod u+x hostflash ; bash ./hostflash

To Run Host Flash™, either

Ensure the script is executable then click to run:

• Right-click > properties > Executable OR chmod u+x hostflash
• click hostflash, or
• type 'bash hostflash or ./host-flash.sh at the command line.

Note: You may need to restart your computer and clear your browser cache(s) for the new hosts file rules to be observed by your OS.

Host Flash™ is being rewritten (we are on version 3.1.8 now). Information below this point may be slightly out of date.

Advanced Usage

Whitelist

The web hosts blocked by the downloaded blacklists may deny you access to a small number of websites that you enjoy visiting.

The presence of a website in one of the downloaded lists does not necessarily imply the site is malicious. If you trust that a blocked website is safe to view you can 'whitelist' it to prevent Host Flash™ blocking access to it.

To whitelist a website, add the website's root address to the .hfwlrc file stored in $HOME.

Notes

	1) DO use hostflash (Option #2 on main menu) to interact with custom lists

	2) DO put each whitelisted domain onto a line of its own

	3) Do add both www and non-www versions of the domain to ensure both versions are whitelisted.

	4) DO NOT include the HTTP or HTTPS part of the domain address i.e the protocol is not required.

	5) DO NOT include anything after the TLD part of the domain.

	6) DO use basic Grep regexes to represent spelling variations of the whitelisted host

	GOOD Examples

		example.com
		www.example.com
		example-two.com
		www.example-two.com
		example[[:num:]].com # This represents example[1-9].com

	BAD Examples

		http://example.com # Do not state the protocol e.g. http://, https:// or ftp: etc...
		www.example.com/ # Do not add anything after the TLD e.g. /
		example-two.com/some-page # Do not add anything after the TLD e.g /some-page
		https://www.example-two.com/one.html # Do not state the protocol. Do not state the page

Wildcard Whitelist

The wildcard whitelist treats any text added to .hfwlwrc as a text fragment to find in any hostname in the hosts file. The search is performed as '[IP ADDRESS][SPACE][anything][HOST FRAGMENT][anything]'.

The regular Whitelist will find and remove only the stated host name from the hosts file searched.

The Wildcard Whitelist will find and remove any host name that includes the host name fragment specified in the whild card whitelist file .hfwlwrc.

The following notes and rules apply to the file .hfwlwrc. Apply the same instructions as explained above for the regular Whitelist with the extra notes that:

6) Try to be as precise as possible when stating the hosts fragment rule to match against host names listed in the hosts file. All matches will be removed from the hosts file.

7) Use basic grep regex patterns to narrow the number of hosts that are likely to match the search fragment.

8) Add a $ character to the end of a host name fragment in the wildcard whitelist if you only want to match sub domains that end with the stated root domain.

	GOOD Examples

		example.com # This will whitelist a.example.com, b.example.com, a.b.example.com and *.example.com.a, *.example.com.b, *.example.com.* etc...
		www.example.com
		example-two.com
		www.example-two.com
		example. # This will whitelist example.com, example.co, example.TLD, *.example.* etc...
		example.com$ # This will whitelist sub domains of example.com. Here example.com is the exact root domain to match against.

	BAD Examples

		http://example.com
		www.example.com/
		example-two.com/some-page
		https://www.example-two.com/one.html

Blacklist

You may want to block access to more hosts than are included in the bad hosts lists downloaded by Host Flash™.

To block extra websites (hosts), add their root addresses (e.g. name.tld) to .hfblrc in $HOME.

Notes

	1) DO use hostflash (Option #2 on main menu) to interact with custom lists
	
	2) DO put each domain to block onto a line of its own.

	3) Do add both www and non-www versions of the domain to ensure both versions are blocked.

	4) DO NOT include the HTTP or HTTPS part of the domain address.

	5) DO NOT include anything after the TLD part of the domain.

	GOOD Examples

		example.com
		www.example.com
		example-two.com
		www.example-two.com

	BAD Examples

		http://example.com
		www.example.com/
		example-two.com/some-page
		https://www.example-two.com/one.html

What to Expect

Your computer will no longer be able to receive data from any of the domains blocked by Host Flash™.

1) When you try to access a page of a blocked domain you will be greeted by a 'Document Not Found' error message that will be served by your computer. This is normal and is what is supposed to happen.

2) Some web pages you visit will display their main content but the places where ads would normally display will now be replaced by Document Not Found messages.

3) Some web pages you visit will display their main content but the places where social media messages normally display will now be replaced by Document Not Found messages.

4) Many web pages will load faster because your web browser will no longer need to wait for ad content to load. This makes web pages lighter so will save bandwidth too.

Linux Virtual Machine Hosts and Hypervisor Hosts that Host Windows Guests

If the environment that Host Flash is being used within is a Virtual Machine host or is a Hypervisor Type 1 (bare-metal) host system then be aware that some source host name blacklists that can be used by Host Flash do block or might at times block Microsoft host names (domains). This may prevent or interfere with the proper functioning of Windows Updates. Remove the Microsoft host names from the blacklist if Windows updates fail or halt unexpectredly.

Remember

If you see a Document Not Found page when you try to visit a website, and you trust the website, add the website's domain to whitelist using Option #2 from the main menu and then use Option #5 to rebuild your hosts file

If you want to block access to additional websites (like social media sites, search engines, adult sites or torrent sites etc...) add their domain names to blacklist.

Quick Note About the IP Address Options

Host Flash™ lets you choose from 4 IP address mapping options. The IP address you choose is the address your computer will call when host names in the list of bad hosts are requested. Here is more information about these options.

0.0.0.0

This IP address is mapped to hosts in some blacklists provided at some hosts repositories. It can be quicker to use 0.0.0.0 instead of other IP addresses because 0.0.0.0 doesn't require the system to wait for a request timeout. This is occasionally also used to resolve a bug in some versions of Windows.

127.0.0.1

This is the typical loopback address of a computer. This is the address normally used to send a request to a bad host (blocked host / website) back to your own computer so that the bad host is never contacted. Use this IP address if 0.0.0.0 is problematic for your OS.

Typical Places for the hosts file to be Installed

For reference, hosts files are typically installed to:

Unix, Unix-like and POSIX: /etc/hosts iOS, Apple Mac: /private/etc/hosts Android: /system/etc/hosts Windows NT, 2000, XP,[5] 2003, Vista, 2008, 7, 2012, 8, 10: %SystemRoot%\System32\drivers\etc\hosts

Introduction to Host Files and Host Flash™

Host Flash™ Protects Computers from Malware, Phishing Sites, Undesirable Content and Adservers.

Host Flash™ installs a list of Internet host domain names that are known to serve ads, malware or other undesirable to view content.

This list of 'bad host' domains is installed into your computer's hosts file.

The hosts file is typically stored in /etc/hosts and is read by your Linux computer when a request is made to view a domain.

As you probably know, DNS servers tell computers the IP address of a server where a website (host) is located. DNS servers are usually managed by ISPs and are only connected to your computer through the incredibly long cables that connect it to the Internet. What you might not know is that your computer's hosts file overrules the remotely managed DNS servers.

Domain names listed in your computer's hosts file are placed next to an IP address. This IP address is the address of the host (or web server) that your computer will attempt to contact when it needs to reach the domain listed alongside it.

IP address to host name maps in a hosts file look like this one:

	127.0.0.1 example.com
	127.0.0.1 example-two.com
	...

Not all domain names (hosts) are listed in a computer's hosts file. In fact, most domain names are not in it. Only those hosts that need their server IP address(es) to be overriden need to be listed in the local hosts file of your computer.

Your computer will not be able to access, send requests to, or recieve content from the domains that are added by Host Flash™ to your computer's local hosts file.

The domains Host Flash™ adds to your hosts file are mapped to either the local IP address (i.e. loopback address) of your computer or to an IP address you specify when Host Flash™ is run. Requests to visit the hosts listed in the hosts file will never get any further than your computer's own IP address.

With the bad hosts blacklist installed you will see (usually) a Document Not Found error message issued by your web browser when you try to view content hosted at a blocked address. This is the normal and expeted behaviour.

Host Flash™ offers you 4 IP address mapping options:

a) 127.0.0.1 (default)
b) 127.255.255.254 (non default)
c) 0.0.0.0 (standard), and
d) Custom

Use the default IP address if in doubt over which to use.

If you wanted to, you could use the IP address of another website so that requests to visit bad hosts redirect to something useful.

Thank You to...

The lists of bad hosts used by Host Flash™ are compiled by, and are available from,

- hosts-file.net
- winhelp2002.mvps.org
- rlwpx.free.fr
- hostsfile.org
- malwaredomainlist.com
- adaway.org
- someonewhocares.org

The program developer Lee Hodson and all who wrote the Linux scripting guides he has read.

Stay Up to Date

Updates to Host Flash™ can be found at either

- https://github.com/VR51/host-flash
- https://host-flash.com

Donations

Give donations to paypal.me/vr51

VR51 is the main fiscal sponsor of Host Flash™.