mattifestation

c:\windows\system32\microsoft\crypto\rsa\machinekeys
c:\windows\system32\tasks_migrated\microsoft\windows\pla\system
c:\windows\syswow64\tasks\microsoft\windows\pla\system
c:\windows\debug\wia
c:\windows\system32\tasks
c:\windows\syswow64\tasks
c:\windows\tasks
c:\windows\registration\crmlog
c:\windows\system32\com\dmp
c:\windows\system32\fxstmp

mattifestation

<?xml version="1.0" encoding="utf-8"?>
<SiPolicy xmlns="urn:schemas-microsoft-com:sipolicy" PolicyType="Base Policy">
  <VersionEx>1.0.0.0</VersionEx>
  <BasePolicyID>{783745D6-2407-458B-9A93-6AD4ACAD1098}</BasePolicyID>
  <PolicyID>{783745D6-2407-458B-9A93-6AD4ACAD1098}</PolicyID>
  <PlatformID>{2E07F7E4-194C-4D20-B7C9-6F44A6C5A234}</PlatformID>
  <Rules>
    <Rule>
      <Option>Enabled:Allow Supplemental Policies</Option>
    </Rule>

mattifestation

<?xml version="1.0" encoding="utf-8"?>
<SiPolicy xmlns="urn:schemas-microsoft-com:sipolicy" PolicyType="AppID Tagging Policy">
  <VersionEx>1.0.0.0</VersionEx>
  <PolicyID>{A244370E-44C9-4C06-B551-F6016E563076}</PolicyID>
  <BasePolicyID>{A244370E-44C9-4C06-B551-F6016E563076}</BasePolicyID>
  <PlatformID>{2E07F7E4-194C-4D20-B7C9-6F44A6C5A234}</PlatformID>
  <Rules>
    <Rule>
      <Option>Enabled:Unsigned System Integrity Policy</Option>
    </Rule>

mattifestation

Microsoft Defender for Endpoint does a great job of ensuring the integrity of the scripts they push and execute.

First, they ensure that the script to execute matches the expected file hash. Example:

powershell.exe -ExecutionPolicy AllSigned -NoProfile -NonInteractive -Command "& {$OutputEncoding = [Console]::OutputEncoding =[System.Text.Encoding]::UTF8;$scriptFileStream = [System.IO.File]::Open('C:\ProgramData\Microsoft\Windows Defender Advanced Threat Protection\DataCollection\7910.6064030.0.6552433-3a7d9fb541a03fc183f740777b7bb1aa20a20efd\046a3caf-d9ec-4da6-a32a-fb148992596a.ps1', [System.IO.FileMode]::Open, [System.IO.FileAccess]::Read, [System.IO.FileAccess]::Read);$calculatedHash = Get-FileHash 'C:\ProgramData\Microsoft\Windows Defender Advanced Threat Protection\DataCollection\7910.6064030.0.6552433-3a7d9fb541a03fc183f740777b7bb1aa20a20efd\046a3caf-d9ec-4da6-a32a-fb148992596a.ps1' -Algorithm SHA256;if (!($calculatedHash.Hash -eq 'd871ab44a81b93cdf3c7e235c246ea8b4bf65d9141d7797270c15dd6bbdb2803'))

mattifestation

<?xml version="1.0" encoding="utf-8"?>
<SiPolicy xmlns="urn:schemas-microsoft-com:sipolicy">
  <VersionEx>10.0.1.0</VersionEx>
  <PolicyID>{A244370E-44C9-4C06-B551-F6016E563076}</PolicyID>
  <BasePolicyID>{A244370E-44C9-4C06-B551-F6016E563076}</BasePolicyID>
  <PlatformID>{2E07F7E4-194C-4D20-B7C9-6F44A6C5A234}</PlatformID>
  <Rules>
    <Rule>
      <Option>Enabled:Unsigned System Integrity Policy</Option>
    </Rule>

mattifestation

Malware Sample Inspected

Trickbot COVID macro lure via MSFT: ec34b207d503a3c95ee743ee296a08e93a5e960aa4611ea8c39d8e5d4c5f6593

test.js

eval("WScript.CreateObject(\"WScript.Shell\").Run(\"calc.exe\");");

mattifestation

# Personal preference. I like landing on the Desktop
Set-Location $Env:USERPROFILE\Desktop

$currentPrincipal = New-Object Security.Principal.WindowsPrincipal([Security.Principal.WindowsIdentity]::GetCurrent())

# If the current session is elevated, prefix the prompt with '[Admin]'
if ($currentPrincipal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
    Set-Item -Path Function:\prompt -Value "`"[Admin] PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) `""
}

mattifestation

# This script requires Win 10 Enterprise to run Get-SystemDriver, unfortunately.

# Note: Get-SystemDriver will take a long time if it has a lot of files and folders to recurse through.
$ScanPath = 'C:\Windows'

# All supported ECC signatures algorithms according to wincrypt.h in the SDK.
$ECCSignatureAlgorithms = @(
    '1.2.840.10045.4.1', # szOID_ECDSA_SHA1
    '1.2.840.10045.4.3', # szOID_ECDSA_SPECIFIED
    '1.2.840.10045.4.3.2', # szOID_ECDSA_SHA256

mattifestation

# Hex string taken from the "para" field of Audit-CVE event ID 1 event in the Application log
$EventParaString = '3081E0020101302C06072A8648CE3D0101022100A9FB57DBA1EEA9BC3E660A909D838D726E3BF623D52620282013481D1F6E5377304404207D5A0975FC2C3057EEF67530417AFFE7FB8055C126DC5C6CE94A4B44F330B5D9042026DC5C6CE94A4B44F330B5D9BBD77CBF958416295CF7E1CE6BCCDC18FF8C07B60441048BD2AEB9CB7E57CB2C4B482FFC81B7AFB9DE27E1E3BD23C23A4453BD9ACE3262547EF835C3DAC4FD97F8461A14611DC9C27745132DED8E545C1D54C72F046997022100A9FB57DBA1EEA9BC3E660A909D838D718C397AA3B561A6F7901E0E82974856A7020101'

# Convert the hex string to a byte array
[Byte[]] $EventParaBytes = $EventParaString -split '([0-9A-F]{2})' | Where-Object { $_ } | ForEach-Object { [Byte] "0x$_" }

# Save the byte array to disk
[IO.File]::WriteAllBytes("$PWD\ECCCurveParams.bin", $EventParaBytes)

# Use certutil to parse the ASN.1-encoded ECC curve parameters

mattifestation

<?xml version="1.0"?>
<SiPolicy xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:schemas-microsoft-com:sipolicy">
  <VersionEx>10.0.0.0</VersionEx>
  <BasePolicyID>{A244370E-44C9-4C06-B551-F6016E563076}</BasePolicyID>
  <PolicyID>{A244370E-44C9-4C06-B551-F6016E563076}</PolicyID>
  <PlatformID>{2E07F7E4-194C-4D20-B7C9-6F44A6C5A234}</PlatformID>
  <Rules>
    <Rule>
      <Option>Enabled:UMCI</Option>
    </Rule>