Match multiple lines with Powershell regex

I use mimikatz to extract NTLM hashes for security audit. The output of mimikatz is along the following lines:

RID  : 000001f4 (500)
User : Administrator

RID  : 000001f5 (501)
User : Guest

RID  : 000001f7 (503)
User : DefaultAccount

RID  : 000001f8 (504)
User : WDAGUtilityAccount
Hash NTLM: 6373ee9aae046ab1319d89b1cfd36306

RID  : 000003e9 (1001)
User : admin
Hash NTLM: f1320e0960da374b88e40cffbec44885

I want to grap the "User" and "Hash NTLM", i.e.,

User : admin
Hash NTLM: f1320e0960da374b88e40cffbec44885 

To do this I use the following regular expression:

[regex]$regex = '(?m)(User\s:\s\w+\r\n\s*Hash NTLM:\s\w+)'

Now, if I use the regular expression directly on the mimikatz output:

$ntlm = Invoke-Expression -Command "mimikatz.exe ""lsadump::sam /sam:C:\sam /system:C:\system"" exit"  
[regex]$regex = '(?m)(User\s:\s\w+\r\n\s*Hash NTLM:\s\w+)'
$regex.Matches($ntlm).value

nothing is returned.

However, if I first store the output to a file and then reads it using -Raw, then it works fine:

$ntlm = Invoke-Expression -Command "mimikatz.exe ""lsadump::sam /sam:C:\sam /system:C:\system"" exit" 
$ntlm | Out-File -FilePath "C:\Users\nlykkei\Desktop\mimikatz.txt"
$Text = Get-Content "C:\Users\nlykkei\Desktop\mimikatz.txt" -Raw
$regex.Matches($Text).value

In this case, the following lines are returned:

User : WDAGUtilityAccount
  Hash NTLM: 6373ee9aae046ab1319d89b1cfd36306
User : admin
  Hash NTLM: f1320e0960da374b88e40cffbec44885

How can I do a proper match without storing the output to a file? I know of \r\n, but they don't seem to work.