Information Technology Notes

Wednesday, October 26, 2022

DNS For Malware Blocking

The Domain Name System protocol maps a human-readable hostname to an IP number. The DNS protocol can be leveraged to filter these lookups. While an application can use a hard-coded IP number, hostname lookups can have any logic or filtering applied by the DNS resolver.

People have effectively self-hosted the Pi-hole solution at home. Typically it is configured to reduce ads which can improve website performance and reduce tracking. For those with some desire to configure a small device, pi-hole is a straightforward and lightweight method to take some control of your network.

There are also hosted DNS solutions which can provide varying levels of filtering and blocking.

Using a phone over a mobile network or public wifi, you may want to have some DNS filtering while not using the Pi-hole solution at home. For an Android phone, there is a setting to allow use of "Private DNS". Go to settings, Network & Internet, Private DNS. If you want to use the Cloudflare DNS offering of 1.1.1.1, Android will require an actual hostname instead of the 1.1.1.1 number scheme. In the settings prompt for Private DNS, enter the hostname 1dot1dot1dot1.cloudflare-dns.com and press save. Your Android phone should then use the Cloudflare DNS filtering. Using one.one.one.one as the hostname seems to have unreliable effects as it does not always properly resolve that name.

Android Private DNS setting:

Look up 1dot1dot1dot1.cloudflare-dns.com which resolves to 1.1.1.1:

Cloudflare's 1.1.1.1 is fast and convenient. For additional levels of filtering, look into using their family filtering at 1.1.1.3. For family filtering, also consider using OpenDNS.

Sunday, January 02, 2022

Tar and Curl in MS Windows 10

I wanted to scp a deep directory structure to a unix machine. In MS Windows 10, I tried to use the File Explorer to click once on the directory and right-click to use the SendTo and choose "Compressed (zipped) folder". That did not work and there was no error message. It simply failed silently.

I opened a PowerShell and found, to my surprise, that both curl and tar are now in Windows 10. To put directories and files into one larger file, the tar command may be used. By itself tar does not compress, though it put everything into one file to make it easier to take a snapshot of a directory structure.

The basics of tar on MS Windows 10 is to open a PowerShell window. Navigate to the top of the directory structure. Type:

tar -cf filename1 filename2 directory3 directory4 newTARfilename.tar

If you want to have ongoing feedback from the command, add the verbose flag:

tar -cvf filename1 filename2 directory3 directory4 newTARfilename.tar

This example uses PowerShell and shows the tar help, the directory, and the tar command.

PS C:\temp\showcompress> tar /?

Usage:

List: tar.exe -tf <archive-filename>

Extract: tar.exe -xf <archive-filename>

Create: tar.exe -cf <archive-filename> [filenames...]

Help: tar.exe --help

PS C:\temp\showcompress> dir

Directory: C:\temp\showcompress

Mode LastWriteTime Length Name

---- ------------- ------ ----

d----- 2021-12-29 15:59 DecemberFolder

PS C:\temp\showcompress> tar -cf DecemberFolder.tar DecemberFolder

PS C:\temp\showcompress> dir

Directory: C:\temp\showcompress

Mode LastWriteTime Length Name

---- ------------- ------ ----

d----- 2021-12-29 15:59 DecemberFolder

-a---- 2021-12-30 00:22 39059677696 DecemberFolder.tar

You may also want to explore the Compress-Archive command in Powershell.

An example curl command will look like:

C:\>curl 2600.com

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">

<title>302 Found</title>

</head><body>

<h1>Found</h1>

<p>The document has moved <a href="https://2600.com/">here</a>.</p>

</body></html>

Tuesday, December 14, 2021

Remove Apps From MS Windows 10

Microsoft is push-installing many more applications in Windows 10. A user may remove some applications by clicking the Start button then right-click on an app and choose uninstall. The uninstall option is not available for many apps installed by Microsoft.

This list of MS Windows 10 PowerShell application removal lines can work on some versions of Windows, and may depend on the current naming and the build number of Windows. The following were tested on several versions of Windows 10, including Microsoft Windows 10 Pro version 10.0.19043 N/A Build 19043.

Right-click on the Start button and choose: Windows PowerShell

If you are not able to run PowerShell as administrator in order to remove the application packages for all users, you will receive an error:
Get-AppxPackage : Access is denied.
Access is denied.

You may instead run the following commands without this option: -Allusers
If the following commands are not working with "-Allusers", try do remove that and run the command again.

If you are looking for application package names to install, try this example for the Solitaire game:

> Get-AppxPackage | select-string "solitaire"

Microsoft.MicrosoftSolitaireCollection_4.4.8204.0_x64__8wekyb3d8bbwe

Then use "solitaire" and remove the game:

Get-AppxPackage *solitaire* | Remove-AppxPackage

List of what you may want to remove. If you are not logged in as administrator, remove "-AllUsers" from the following:

Get-AppxPackage Microsoft.YourPhone -AllUsers | Remove-AppxPackage
# or
Get-AppxPackage *windowsphone* -AllUsers | Remove-AppxPackage

Get-AppxPackage *xbox* -AllUsers | Remove-AppxPackage

Get-AppxPackage *3dbuilder* -AllUsers | Remove-AppxPackage

Get-AppxPackage Microsoft.Microsoft3DViewer -AllUsers | Remove-AppxPackage

Get-AppxPackage *people* -AllUsers | Remove-AppxPackage
# or
Get-AppxPackage Microsoft.Windows.PeopleExperienceHost -AllUsers | Remove-AppxPackage
# or
Get-AppxPackage Microsoft.people -AllUsers | Remove-AppxPackage

# Cortana
Get-AppxPackage Microsoft.549981C3F5F10 -AllUsers | Remove-AppxPackage

Get-AppxPackage *Microsoft.GetHelp* -AllUsers | Remove-AppxPackage

Get-AppxPackage *windowsalarms* -AllUsers | Remove-AppxPackage

Get-AppxPackage *windowscommunicationsapps* -AllUsers | Remove-AppxPackage

Get-AppxPackage *skypeapp* -AllUsers | Remove-AppxPackage

Get-AppxPackage *officehub* -AllUsers | Remove-AppxPackage

Get-AppxPackage *getstarted* -AllUsers | Remove-AppxPackage

Get-AppxPackage *onenote* -AllUsers | Remove-AppxPackage

Get-AppxPackage *bingweather* -AllUsers | Remove-AppxPackage

Get-AppxPackage *windowscamera* -AllUsers | Remove-AppxPackage

Get-AppxPackage *windowsmaps* -AllUsers | Remove-AppxPackage

Get-AppxPackage Microsoft.WindowsFeedbackHub -AllUsers | Remove-AppxPackage

Get-AppxPackage *music* -AllUsers | Remove-AppxPackage

Get-AppxPackage *solitaire* -AllUsers | Remove-AppxPackage

Get-AppxPackage *portal* -AllUsers | Remove-AppxPackage

Get-AppxPackage *stickynotes* -AllUsers | Remove-AppxPackage

# Movies & TV

Get-AppxPackage *zunevideo* -AllUsers | Remove-AppxPackage

# Snip & Sketch
Get-AppxPackage *screensketch* -AllUsers | Remove-AppxPackage

# Sound Recorder
Get-AppxPackage *soundrecorder* -AllUsers | Remove-AppxPackage

Microsoft OneDrive may be removed from within the legacy "Control Panel" application. Press Start button, then begin typing "control panel".

After you have uninstalled applications, it is usually useful to create a Windows "restore point" to snapshot the current configuration. If you feel more advanced, you may want to explore the "Services" app to stop services you may not be using.