Using the Scan Assistant

The Scan Assistant provides you with a secure alternative for authenticated scans that utilizes elliptic curve asymmetric encryption (ECDSA) and advanced encryption standard (AES) to form a trusted secure channel between the Scan Assistant and the Scan Engine. You can deploy the Scan Assistant with a public certificate in your environment which allows the Scan Engine to receive a private certificate.

The Scan Assistant achieves the same results as a credential scan without the need for administrative credential management and provides accurate, granular vulnerability fingerprinting and assessment for assets. The Scan Assistant allows the Scan Engine to connect directly to an endpoint in order to collect data without the need for additional credentials. A secure connection is created between the Scan Engine and the Scan Assistant by using elliptic curve asymmetric encryption (ECDSA) and advanced encryption standard (AES).

Once installed, the Scan Assistant provides Registry and File System services (Windows) or a Command Execution Service (Linux) on the local asset, and only runs when scans are performed.

Why should I use the Scan Assistant?

The Scan Assistant provides a more secure way to scan your assets, removes the need for administrative credential management, consumes much fewer resources, and significantly decreases the time to complete for policy scans.

When should I use the Scan Assistant?

The Scan Assistant provides an additional tool that Nexpose and InsightVM administrators can leverage to expand and extend enterprise vulnerability coverage. It is complementary to the Insight Agent, and compatible with the InsightVM cloud platform, but does not require cloud connectivity. The Scan Assistant provides an ideal solution for the following vulnerability coverage scenarios:

Resource Utilization

The Scan Assistant will occupy approximately 20MB in memory. It will consume 0% CPU when idle. CPU utilization can range from 2.5% to 6% when the Scan Assistant is active, for a duration of 60 to 120 seconds while a scan is completed.

Scan Assistant Deployment Overview

Windows

1. Download the Scan Assistant software (.MSI) and the Checksum (SHA512 file).
2. Create and deploy X.509 digital certificates, that will be used to establish a trusted connection between the Scan Engine and scanned assets.
3. Configure and schedule scans for Sites with assets that have the Scan Assistant installed.

A Public Key (PEM) is added with the Scan Assistant software and to all supported target assets as part of the installation. A Private Key(included in a PKCS12 file) is added to the Security Console as a scan credential.

Microsoft Standard Installer (Msiexec.exe) is used to install the Scan Assistant software .MSI and one line PEM file with the /i command line parameter. Additional command line parameters can be seen by running Msiexec.exe, or found in Microsoft’s documentation. This information may prove useful in creating automated installation scripts.

Linux

1. Download the Scan Assistant packages (.DEB or .RPM) and Checksum (SHA512 files).
2. Create and deploy X.509 digital certificates, that will be used to establish a trusted connection between the Scan Engine and scanned assets.
3. Configure and schedule scans for Sites with assets that have the Scan Assistant installed.

A Public Key (PEM) is added with the Scan Assistant software and to all supported target assets as part of the installation. A Private Key (included in a PKCS12 file) is automatically added to the Security Console as a scan credential.

Standard Linux Package Managers for Debian (.DEB) or Red Hat Linux (.RPM) distributions are used to install the Scan Assistant software. Be certain to use the appropriate package for your Linux variant. A one line PEM file automatically generated via the Rapid7 Security Console will be pasted into the Scan Assistant config.json file in each scanned asset. Alternatively, the PEM file may be placed in the same directory as the config.json file.

Linux Scan Assistant Credentials

Existing Windows Scan Assistant credentials may be re-used with the Scan Assistant for Linux. A single set of Scan Assistant credentials can be shared across Windows and Linux assets."

Uninstall the Early Access binary version of Scan Assistant for Linux

If you installed the Scan Assistant using the binary provided for the Early Access version and you want to use the Scan Assistant package manager version instead, you must first uninstall the binary version.

Installing and configuring for Windows

Supported Windows Platforms

The Scan Assistant supports the following platforms:

• Windows 10
• Windows 11
• Windows Server 2016
• Windows Server 2019
• Windows Server 2022

Task 1: Download the Windows Installer and Checksum

Before setting up the Scan Assistant, you must download the MSI and checksum.

Task 2: Add port to Service Discovery and Asset Discovery

You must add TCP port 21047 to both Service Discovery and Asset Discovery for all scan templates before setting up the Scan Assistant.

Task 3: Generate the Scan Assistant Credentials

You can automatically generate the Scan Assistant credentials in the InsightVM Console. When generating new Scan Assistant credentials, previous credentials are not automatically deleted. You can set up automatic certificate rotation or delete your old credentials.

1. From the Administration tab click Shared Credentials.
2. Click New.
3. On the General tab, enter a unique name and description.
4. On the Account tab, in the Service field, select Scan Assistant.
5. Select the Generate checkbox. By selecting this checkbox, your scan credentials are automatically generated once the credential is saved.
6. On the Site Assignment tab, specify what sites can use the credential.
   • To allow all sites to access the credential, select Assign these credentials to all current and future sites.
   • To select a specific set of sites to access the credential, click Select Sites, select the sites you want to allow to use the credential, and click Add Sites.
7. Click Save. You are redirected back to the Administration page.
8. Click Shared Credentials.
9. Click Edit on your newly created Scan Assistant shared credential.
10. Copy the automatically generated PEM file.

Task 4: Install the Scan Assistant on Windows

Asset Configuration Details

When installed, the Scan Assistant automatically configures the required parameters on the asset. It adds itself as a service that starts automatically and adds itself to the Windows firewall, listening on TCP port 21047. It also adds itself as an event source to the Windows eventlog and supports audit logging when required. When uninstalled, the Scan Assistant removes all changes made to the asset.

The following table shows additional Windows asset configuration.

Asset deployment Notes

When the Scan Assistant is used, the following configurations and services that may have been required on the target Windows assets to enable traditional credentialed scans are no longer needed:

• Remote access to an Administrative account
• Remote access to built-in Windows services
• Enable the Windows Registry services
• Enable the WMI service
• Enable the WinRM service
• Enable File & Print sharing, or equivalent services

Installing and configuring for Linux

Scan Engine version

Scan Assistant for Linux requires your Scan Engine to be at 6.6.153 or higher.

Supported Linux Platforms

The Scan Assistant for Linux should install on any Linux distribution that supports Debian (.DEB), Red Hat (.RPM) Package Managers, systemd or upstart Service Managers.

Linux distributions that have been tested are listed in the table below. Note that the Scan Assistant for Linux may also install on other Linux distributions that meet the criteria listed above.

Linux distributions by service manager and package manager

Task 1: Download Scan Assistant for Linux Packages and Checksums

Before setting up the Scan Assistant, you must download the appropriate package and checksum for your Linux distribution and package manager.

• Download the Debian (.DEB) package and checksum.

• Download the .RPM / Redhat Package Manager (.RPM) and checksum.

Key file locations

• The Scan Assistant binary can be found at the following path: /usr/sbin/ScanAssistant.
• The Scan Assistant configuration file (config.json) and asset one-line PEM file will reside in: /etc/rapid7/ScanAssistant. The config.json file will be automatically created as part of the installation.

Generate Scan Assistant credentials

The Scan Assistant leverages X.509 digital certificates, to establish a trusted connection between the Scan Engine and scanned assets.

Scan Assistant credentials can be generated automatically from the Security Console Shared Credentials interface. You can find more information on generating Scan Assistant credentials here. Also, you must copy the automatically generated PEM file for use with your Linux asset installation.

Task 2: Install the package

Scan Assistant packages are available for Debian (.DEB) and Red Hat (RPM) based distributions.

Linux configuration files

The Scan Assistant for Linux uses a configuration file called config.json. This file contains a number of parameters that are required for the Scan Assistant to function.

• The config.json contains a field called PackageManager which specifies the package manager to be used on the asset (.DEB or .RPM). This means that a single config.json cannot be used enterprise wide for Scan Assistant for Linux installations.

• There are two options for the initial location of the PEM file on the asset. It can be pasted into the config.json, or it can be contained in a separate file named scan-assistant.pem, located in the same directory as the config.json (/etc/rapid7/ScanAssistant).

.DEB package installation

Debian based systems use the dpkg command to install .DEB packages.

1. At a command prompt (in Linux also called Terminal Window) issue the following command from the directory where the Scan Assistant package is located: sudo dpkg -i R7ScanAssistant_amd64.deb.

2. Verify the following lines are in the output:

    
   1
    Service action: "install"
   2
    Service action: complete
   3
    Service action: "start"
   4
    Service action: complete

If you are unable to see the output, the Scan Assistant may be installed but it is not running. Contact Support to receive assistance with this issue.

3. From a terminal window, edit the configuration file located at /etc/rapid7/ScanAssistant/config.json. The one line PEM file that was created on the Security Console can be pasted into the config.json between the quotations in the ClientCertificate field.

The client certificate may optionally appear as a separate PEM file in the same directory. When using this method the PEM file must be named scan-assistant.pem. Note that if the Scan Template automatic certificate update feature is used, the PEM file will be automatically inserted into the config.json from that point forward. The external scan-assistant.pem will remain in place as a previously used credential.

Config.json

 
1
{
2
"ClientCertificate": "",
3
"ResponseTimeout": 300,
4
"Debug": false,
5
"PackageManager": "deb"
6
 } 

4. Methods to verify the installation:

   • List installed packages
     • Enter: Enter sudo dpkg-query -l | grep r7scanassistant
   • Check for service in memory status: ps -ef | grep ScanAssistant

.RPM package installation

Red Hat-based systems use the rpm command to install .RPM packages

1. In the command prompt install sudo rpm -ivh R7ScanAssistant_amd64.rpm.

2. Verify the following lines are in the output:

    
   1
    Service action: "install"
   2
    Service action: complete
   3
    Service action: "start"
   4
    Service action: complete

If you are unable to see the output, the Scan Assistant may be installed but it is not running. Contact Support to receive assistance with this issue.

3. From a terminal window, edit the configuration file located at /etc/rapid7/ScanAssistant/config.json. The one line PEM file that was created on the Security Console can be pasted into the config.json between the quotations in the ClientCertificate field.

The client certificate may optionally appear as a separate PEM file in the same directory. When using this method the PEM file must be named scan-assistant.pem. Note that if the Scan Template automatic certificate update feature is used, the PEM file will be automatically inserted into the config.json from that point forward. The external scan-assistant.pem will remain in place as a previously used credential.

Config.json

 
1
{ 
2
"ClientCertificate": "",
3
"ResponseTimeout": 300,
4
"Debug": false,
5
"PackageManager": "rpm"
6
}

4. Methods to verify the installation:

   • List installed packages
     • Enter: rpm -q R7scanassistant_amd64 -i
   • Check for service in memory status: ps -ef | grep ScanAssistant

Example output of verifying installation

 
1
``` 
2
  json                                                                             
3
  
4
  Name: R7ScanAssistant
5
  Epoch: 0
6
  Version: 1.2.1
7
  Release: 1
8
  Architecture: x86_64
9
  Install Date: Mon 15 Aug 2022 05:31:15 PM UTC
10
  Group:
11
  Size: 9151866
12
  License:
13
  Signature: (none)
14
  Source RPM: R7ScanAssistant.src.rpm
15
  Build Date: Thu 11 Aug 2022 10:21:24 PM UTC
16
  Build Host: AUS-MBP-6346
17
  Relocations: (not relocatable)
18
  Packager: Rapid7
19
  Vendor: Rapid7
20
  URL:
21
  Summary: Rapid7 InsightVM Scan Assistant
22
  Description: Rapid7 InsightVM Scan Assistant  
23
``` 

Automatic Certificate Rotation

In the Scan Assistant template, you can automatically rotate your Scan Assistant certificate. When you enable certificate rotation, InsightVM automatically attempts to update the Scan Assistant to use the available credential with the latest expiration date.

You can not explicitly set the expiration date for certificates that are automatically generated from the Security Console. The default validity period for certificates is three years, so the most recent certificate added will have the longest validity period. To enable the certificate rotation, you will need to create a new certificate pair from the Security Console according to your IT Security policy for digital certificate or credential rotation.

Rapid7 recommends deleting the oldest certificate every 3rd new certificate. Keep in mind that this recommendation is not necessarily the timeframe but in accordance with your internal certificate rotation policy. The frequency of rotation is usually set by your IT Security Policy. You may choose to rotate the certificates in accordance with your Security Policy before they expire.

Scan Assistant Software Updates

When you enable automatic updates, InsightVM updates the Scan Assistant with the latest installation, when available. Automatic updates are available for the Scan Assistant for Windows versions 1.1.0 and Linux versions 6.6.153. Automatic updates are also available for later versions of Windows and Linux.

1. Select the Administration tab.
2. Click Scans > Templates. Select the template you want to edit or click New Scan Template.
3. On the Scan Assistant tab select the Rotate Certificates checkbox, to automatically rotate your Scan Assistant certificates.
4. Select the Apply Updates checkbox, to automatically apply the latest updates.
5. Click Save.

For optimal scan performance with the Scan Assistant, Rapid7 recommends selecting either the Automatic Certificate Rotation or the Scan Assistant Software Updates feature, but not both in the same scan template. Enabling both features in the same scan template affects the scan performance issues when a Scan Assistant update or Credential rotation occurs.

Uninstall the Scan Assistant from a Windows asset

Command line

You can uninstall the Scan Assistant from a Windows asset by utilizing the command line.

The Windows Scan Assistant ships as an .msi file and uses the standard Microsoft Windows installer, msiexec.exe. Refer to Microsoft’s documentation to view all the listed command line options. Also, you can see the command line options by running msiexec from a CMD prompt on a Windows Machine.

UI

You can also uninstall the Scan Assistant from a Windows asset from Windows Explorer and the add or remove programs applet.

Windows Explorer

If you are at the keyboard of the Windows asset, you can use Windows Explorer to uninstall.

1. Navigate to ScanAssistantInstaller.msi.

The location of the ScanAssistantInstaller will be based on the folder or directory you chose to place it in.

2. Right click on the .msi and select Uninstall.

Programs applet

You can uninstall the Scan Assistant from the add or remove programs applet. On Windows 10, if you search for Add in the Windows search bar, you will see the add or remove programs applet.

Uninstall the Scan Assistant from a Linux asset

.DEB packages

1. From a terminal window issue the following command: sudo dpkg -r r7ScanAssistant

2. Verify the following lines in the command output:

    
   1
    Service action: "stop"
   2
    Service action: complete
   3
    Service action: "uninstall"
   4
    Service action: complete

.RPM packages

1. From a terminal window issue the following command: rpm -e r7ScanAssistant

2. Verify the following lines in the command output:

    
   1
    Service action: "stop"
   2
    Service action: complete
   3
    Service action: "uninstall"
   4
    Service action: complete

Mass deployment

For mass deployments of the Scan Assistant for Linux a unique config.json must be created for groups of assets using each package manager (.DEB or .RPM).

The following tools may be used to automate mass installations of the Scan Assistant:

• Microsoft SCCM (System Center Configuration Manager
• Microsoft GPO (Group Policy Orchestrator)
• HCL BigFix
• Red Hat Ansible
• Intune
• PDQ Deploy

(Documentation for each tool set is available from the respective vendor.)

Frequently Asked Questions

 
1
$mypassword = ConvertTo-SecureString -String "PASSWORD" -Force -AsPlainText
2
Export-PfxCertificate -Cert Cert:\LocalMachine\My\THUMBPRINT -FilePath scan-assistant.pfx -Password $mypassword

 
1
$oMachineCert=Get-Item Cert:\LocalMachine\My\THUMBPRINT
2
$InsertLineBreaks=0
3
$oPem=new-object System.Text.StringBuilder
4
$oPem.Append("-----BEGIN CERTIFICATE----- ")
5
$oPem.Append([System.Convert]::ToBase64String($oMachineCert.RawData, $InsertLineBreaks))
6
$oPem.Append(" -----END CERTIFICATE-----")
7
$oPem.ToString()

 
1
Remove-Item -Path cert:\LocalMachine\My\581C1CA18731790790CF7392DC3510CFA5382BBD -DeleteKey
2

3
Remove-Item -Path cert:\LocalMachine\My\THUMBPRINT -DeleteKey