Skip to main content

Determine what Clients a User has Logged into when the Client is Offline

This one was a bit tricky.  The idea is to match a logon event of a user to one of a client via a common piece of data.  That data is the IP address.

This code is not thoroughly tested.  It utilizes the Security logs from a Domain controller.  It looks for event  4768.  Both the user login and the client login will contain an IP address inside the message portion.  It then looks through the records to match User Name and Client Name using the IP Address.  A few things to consider:

1) This will need to be executed against each Domain Controller.  Since you do not know which DC the client is bound to, your will need to check all of them.

2) In a large environment with large security logs, this will take some time.

3) The code is not optimized.  I’ll leave that fun up to you.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

# Creates the object that will be used to store information from the event logs.

Function New-LogObject

{

    $Obj = New-Object -TypeName PSObject -Property @{

        "UserName" = $Null

        "IPAddress" = $Null

        "Record" = $Null

        "Client" = $Null

        "TimeGenerated" = $Null

 

    }

    Write-Output $Obj

}

 

# Creates an object that will be the final product of this code.

Function New-MatchObject

{

    $Obj = New-Object -TypeName PSObject -Property @{

        "UserName" = $Null

        "Client" = $Null

        "TimeGenerated" = $Null

 

    }

    Write-Output $Obj

}

 

# Retrieve the first 100 events of event ID 4768

$Events = Get-EventLog -LogName Security -InstanceId 4768 -Newest 100

 

# Allocates dynamic memory.

$Data = @()

 

 

# Loop through each event and identify the key parts.

ForEach ($E in $Events)

{

  

   # User Record.

   If ((($E.Message).Split("`n"))[3] -notlike "*$*")

   {

        $Obj = New-LogObject

 

        # Extract the username.

        $Obj.UserName = (($E.Message).Split("`n"))[3].Replace("Account Name:",$Null).Trim()

 

  

        # Extract the IP Address.

        If ((($E.Message).Split("`n"))[12] -match "\d+.\d+.\d+.\d+")

        {

            $Obj."IPAddress" = $Matches.Values

        }

 

        $Obj.Record = "User"

        $Obj.TimeGenerated = $E.TimeGenerated

   }

   ElseIf ((($E.Message).Split("`n"))[3] -like "*$*")

   {

        $Obj = New-LogObject

 

        # Extract the username.

        $Obj.Client = (($E.Message).Split("`n"))[3].Replace("Account Name:",$Null).Trim()

 

  

        # Extract the IP Address.

        If ((($E.Message).Split("`n"))[12] -match "\d+.\d+.\d+.\d+")

        {

            $Obj."IPAddress" = $Matches.Values

        }

 

        $Obj.Record = "Client"

   }

 

   # Record the object in the Dynamic memory.

   $Data += $Obj

} # END: ForEach ($E in $Events)

 

# Compare records and match users to clients.

$Data2 = @()

For ($X=0 ;$X -lt $Data.count; $X++)

{

    For ($Y = $X+1; $Y -lt $Data.count; $Y++)

    {

        If (($Data[$X].IPAddress -eq $Data[$Y].IPAddress) -and ($Data[$X].Record -eq "User") -and  ($Data[$Y].Record -eq "Client"))

        {

            $Obj = New-MatchObject

            $Obj.UserName = $Data[$X].UserName

            $Obj.Client = $Data[$Y].Client

            $Obj.TimeGenerated = $Data[$X].TimeGenerated

 

            $Data2 += $Obj

        }

    }

}

 

$Data2 | Sort-Object -Property TimeGenerated -Unique -Descending

Comments

Popular posts from this blog

Adding a Comment to a GPO with PowerShell

As I'm writing this article, I'm also writing a customization for a PowerShell course I'm teaching next week in Phoenix.  This customization deals with Group Policy and PowerShell.  For those of you who attend my classes may already know this, but I sit their and try to ask the questions to myself that others may ask as I present the material.  I finished up my customization a few hours ago and then I realized that I did not add in how to put a comment on a GPO.  This is a feature that many Group Policy Administrators may not be aware of. This past summer I attended a presentation at TechEd on Group Policy.  One organization in the crowd had over 5,000 Group Policies.  In an environment like that, the comment section can be priceless.  I always like to write in the comment section why I created the policy so I know its purpose next week after I've completed 50 other tasks and can't remember what I did 5 minutes ago. In the Group Policy module for PowerShell V3, th

Return duplicate values from a collection with PowerShell

If you have a collection of objects and you want to remove any duplicate items, it is fairly simple. # Create a collection with duplicate values $Set1 = 1 , 1 , 2 , 2 , 3 , 4 , 5 , 6 , 7 , 1 , 2   # Remove the duplicate values. $Set1 | Select-Object -Unique 1 2 3 4 5 6 7 What if you want only the duplicate values and nothing else? # Create a collection with duplicate values $Set1 = 1 , 1 , 2 , 2 , 3 , 4 , 5 , 6 , 7 , 1 , 2   #Create a second collection with duplicate values removed. $Set2 = $Set1 | Select-Object -Unique   # Return only the duplicate values. ( Compare-Object -ReferenceObject $Set2 -DifferenceObject $Set1 ) . InputObject | Select-Object – Unique 1 2 This works with objects as well as numbers.  The first command creates a collection with 2 duplicates of both 1 and 2.   The second command creates another collection with the duplicates filtered out.  The Compare-Object cmdlet will first find items that are diffe

How to list all the AD LDS instances on a server

AD LDS allows you to provide directory services to applications that are free of the confines of Active Directory.  To list all the AD LDS instances on a server, follow this procedure: Log into the server in question Open a command prompt. Type dsdbutil and press Enter Type List Instances and press Enter . You will receive a list of the instance name, both the LDAP and SSL port numbers, the location of the database, and its status.