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PowerShell | Dump all Variables / Objects to a Text File

Super quick post. Ever working on a automation engine and wondering what objects are at your disposal? Or perhaps you simply just want to see all properties available to your workspace?

Give this a try:

Get-Variable | ConvertTo-Json

 

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Secure PowerShell Scripts running via Windows Task Scheduler using MD5 Hashes to safeguard against Tampering

Over the years the number of Task Scheduled based PowerShell scripts has increased. However, this poses serious potential security risks.

The Security Issue

Given that these tasks commonly run as a service account, with additional rights, it is a potential attack vector.

Simply changing the underlying script can allow a hacker access to anything the service account has access to.Even signing the scripts can be useless as the system can be configured to ignore signing.

The Solution

I have created this one-liner that Task Scheduler can use that will only run the script if the hash of the script matches the hash listed in the one-liner. If someone tries to change this in Task Scheduler they would be required to reenter the proper password.

powershell.exe -command if ([System.BitConverter]::ToString((New-Object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider).ComputeHash([System.IO.File]::ReadAllBytes(‘C:\temp\test.ps1‘))) -eq ‘33-CD-2A-54-ED-F3-0F-94-5F-D2-97-D9-FE-4F-45-79‘) {. c:\temp\test.ps1} else {Send-MailMessage -SmtpServer smtp.server.domain.com -From whatever@domain.com -To you@domain.com -Subject ‘Failed to Run Script – Hash Not Correct’}

Notes about One Line Script Executor

  • You need to replace c:\temp\test.ps1 with the path to your script. (two places in this example)
  • You must supply the hash of the script. (use the following command to get it)

[System.BitConverter]::ToString((New-Object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider).ComputeHash([System.IO.File]::ReadAllBytes(‘C:\temp\test.ps1‘)))

  • Script will email you if hash fails.
    • Change TO: and FROM: to match your needs.
  • Do NOT use double quotes in this script, do NOT forget that CMD will pass this to PowerShell, and will strip out double quotes.

If this helped you or perhaps you have suggestions to make it better, please do leave them in the comments.

Enjoy

-Eric

Search Active Directory for Specific Word or Phrase (string) in a Group

Ever tried to search for a group by name but the part you know is in the middle? Did you think you would be smart and go to the advanced tab then do “blah” contains, hit search and find nothing?

Quickest way to find is actually via PowerShell

Get-ADGroup -Filter {Name -like “*blah*”} | select SAMAccountName

Works great!

Enjoy

-Eric

Powershell | Using Modify AD Groups with Alternate Credentials

Quick one. Had an issue where I needed to remove a user from a AD group in another domain. To my surprise it was harder then I had thought. At first I settled on using set-QADGroupMember (the Quest Powershell CMDLET) as it takes -connectionusername and -connectionpassword. However it was dog slow. I think that was due to being over a WAN link and it was querying all members (which took about 2-3 mins).

I needed something swifter. I went directly to the .NET controls and reduced the time to about 15 second.

$GroupDN = “LDAP://CN=GroupName,OU=Distribution Lists,DC=domain,DC=local”
$Group = New-Object -TypeName System.DirectoryServices.DirectoryEntry -ArgumentList $GroupDN,”username”,”Password”
#To Add
$Group.Properties[“member”].Add(“DN of the User you wish to add”)
#To Remove
$Group.Properties[“member”].Remove(“DN of the User you wish removed”)
$Group.CommitChanges()
$Group.Close()

Enjoy!

-Eric

Powershell | Get Current User Principle Name (UPN)

Quicky,

I had a need to write a Powershell script that would figure out what the current users UPN (User Principle Name) was. Believe it or not I was dumbfounded there wasn’t a good post on it anywhere.  So here is the code:

 

$strFilter = “(&(objectCategory=User)(SAMAccountName=$Env:USERNAME))”
$objDomain = New-Object System.DirectoryServices.DirectoryEntry
$objSearcher = New-Object System.DirectoryServices.DirectorySearcher
$objSearcher.SearchRoot = $objDomain
$objSearcher.PageSize = 1
$objSearcher.Filter = $strFilter
$objSearcher.SearchScope = “Subtree”
$objSearcher.PropertiesToLoad.Add(“userprincipalname”) | Out-Null
$colResults = $objSearcher.FindAll()

$UPN = $colResults[0].Properties.userprincipalname
$UPN

 

Enjoy, if you needed this and found it here please let me a comment, always glad to hear when these things help people out!

Powershell | The Last $Error and Emailing it

OMG some things in Powershell are just too confusing to be useful. What if you need to see the last error message again. What if you want to write it into your script to email you when the error happens?

Well first, its all in $Error

However, $Error is an array.  To access it really requires notation like this:

$Error[0]

The [0] says give me back the last error. Where [1] would say to give me back the second to last error message.

The Problem….

Ok now here is where it gets “funky”. If you just type $Error[0] you get the entire error message like so: (note I am using an error message from some Lync work I have been doing, the names have been changed to protect well me lol)

Set-CsUser : Management object not found for identity “Jerry.Springer@Contoso.com”.
At C:\Scripts\EnableLyncUsers.ps1:138 char:15
+                 Set-CsUser <<<<  -Identity $user.UserPrincipalName -SipAddress $user.UserPrincipalName
    + CategoryInfo          : NotSpecified: (:) [Set-CsUser], ManagementException
    + FullyQualifiedErrorId : Microsoft.Rtc.Management.AD.ManagementException,Microsoft.Rtc.Management.AD.Cmdlets.S
   etOcsUserCmdlet

BUT…. if you type write-host $Error[0] you get this:

Management object not found for identity “Jerry.Springer@Contoso.com”.

So what gives right??? Why when you use Write-Host OR even better when you try to email $Error[0] do we get the crappy short error message? Well I don’t have the answer BUT I do have a great work around.

The Solution….

[string]$ErrorString = $Error[0].Exception
[string]$ErrorString = $ErrorString + ” `n `n ”
[string]$ErrorString = $ErrorString + $Error[0].InvocationInfo.PositionMessage

(that’s 3 lines BTW)

As far as I can tell the only thing one needs are the short error message and the line, script, and command. To do this use the code above and then simply use Write-Host or email that new $ErrorString variable. If you need other data follow the info below from how I figured this out.

Emailing the Error? Simply use this code (replace stuff inside of < > then remove the < >):

    [string]$ErrorString = $Error[0].Exception
    [string]$ErrorString = $ErrorString + ” `n `n ”
    [string]$ErrorString = $ErrorString + $Error[0].InvocationInfo.PositionMessage

    $SmtpClient = new-object system.net.mail.smtpClient
    $MailMessage = New-Object system.net.mail.mailmessage
    $SmtpClient.Host = “<SMTP IP OR NAME>”
    $mailmessage.from = <from@domain.com>
    $mailmessage.To.add(“email1@domain.com,email2@domain.com”)
    $mailmessage.Subject = “<Subject of Email>”
    $MailMessage.IsBodyHtml = $false
    $mailmessage.Body = $ErrorString
 
    $smtpclient.Send($mailmessage)

How did I figure this out?

First I indexed $Error to get me the first result [0]

Next I used the power of Get-Member

$Error[0] | Get-Member

This dumped out all the properties

TypeName: System.Management.Automation.ErrorRecord

Name                  MemberType     Definition                                                                    
—-                  ———-     ———-                                                                    
Equals                Method         bool Equals(System.Object obj)                                                
GetHashCode           Method         int GetHashCode()                                                             
GetObjectData         Method         System.Void GetObjectData(System.Runtime.Serialization.SerializationInfo inf…
GetType               Method         type GetType()                                                                
ToString              Method         string ToString()                                                             
CategoryInfo          Property       System.Management.Automation.ErrorCategoryInfo CategoryInfo {get;}            
ErrorDetails          Property       System.Management.Automation.ErrorDetails ErrorDetails {get;set;}             
Exception             Property       System.Exception Exception {get;}                                             
FullyQualifiedErrorId Property       System.String FullyQualifiedErrorId {get;}                                    
InvocationInfo        Property       System.Management.Automation.InvocationInfo InvocationInfo {get;}             
PipelineIterationInfo Property       System.Collections.ObjectModel.ReadOnlyCollection`1[[System.Int32, mscorlib,…
TargetObject          Property       System.Object TargetObject {get;}                                             
PSMessageDetails      ScriptProperty System.Object PSMessageDetails {get=& { Set-StrictMode -Version 1; $this.Exc…

All of the properties normally can be accessed like this:

$Error[0].Exception

But if you try to write-host $Error[0].InvocationInfo you get:

System.Management.Automation.InvocationInfo

Well that’s not very useful… the reason for this is there are deeper items in the $Error[0].InvocationInfo tree. So if we go ahead and whip out get-member again on $Error[0].InvocationInfo lets see what we get:

TypeName: System.Management.Automation.InvocationInfo

Name             MemberType Definition                                                                             
—-             ———- ———-                                                                             
Equals           Method     bool Equals(System.Object obj)                                                         
GetHashCode      Method     int GetHashCode()                                                                      
GetType          Method     type GetType()                                                                         
ToString         Method     string ToString()                                                                      
BoundParameters  Property   System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=2.0.0.0, Cu…
CommandOrigin    Property   System.Management.Automation.CommandOrigin CommandOrigin {get;}                        
ExpectingInput   Property   System.Boolean ExpectingInput {get;}                                                   
HistoryId        Property   System.Int64 HistoryId {get;}                                                          
InvocationName   Property   System.String InvocationName {get;}                                                    
Line             Property   System.String Line {get;}                                                              
MyCommand        Property   System.Management.Automation.CommandInfo MyCommand {get;}                              
OffsetInLine     Property   System.Int32 OffsetInLine {get;}                                                       
PipelineLength   Property   System.Int32 PipelineLength {get;}                                                     
PipelinePosition Property   System.Int32 PipelinePosition {get;}                                                   
PositionMessage  Property   System.String PositionMessage {get;}                                                   
ScriptLineNumber Property   System.Int32 ScriptLineNumber {get;}                                                   
ScriptName       Property   System.String ScriptName {get;}                                                        
UnboundArguments Property   System.Collections.Generic.List`1[[System.Object, mscorlib, Version=2.0.0.0, Culture=…

Ah… there’s more stuff. Lastly I just needed to figure out what items inside of $Error[0].InvocationInfo I needed. Turns out just one thing. So to write-host it all I needed to do is call:

Write-Host $Error[0].InvocationInfo.PositionMessage

Hope that opens your mind to how more complex objects work in Powershell.

Hey!

Did I help? Make Sense? Something Wrong? Put it in the comments. Love to hear when my write-ups help folks out.

Enjoy

-Eric

Get all SMTP Address from Public Folders or Groups or anything in Exchange!

Here is a quick one, just change your mail domain where it says “MyDomain.com”

Public Folders Only:

Get-recipient -RecipientTypeDetails PublicFolder | select Name -ExpandProperty EmailAddresses | ? {$_.SMTPAddress -like “*MyDomain.com*”} | select Name, SMTPAddress

To pump to CSV:

Add this to the end: | Export-CSV C:\Filename.csv

Other  RecipientTypeDetails types? Just change the RecipientTypeDetails to one or more of the following (comma delimited):

  • MailUniversalDistributionGroup
  • MailUniversalSecurityGroup
  • DynamicDistributionGroup
  • MailNonUniversalGroup
  • MailUser
  • UserMailbox
  • PublicFolder
  • MailContact
  • DiscoveryMailbox
  • SharedMailbox
  • RoomMailbox