Overview

This document contains frequently asked questions (FAQ) about the Arctic Wolf® Managed Risk® Scanner, including Internal Vulnerability Assessment (IVA) scanning.

See Managing Risk Scanner configuration in the Risk Dashboard User Guide for more information about Risk Scanner configuration.

Contact your Concierge Security® Team (CST) if you have questions that are not covered here.

Scanner installation and configuration FAQs

Q: Where in the network should I deploy the scanner?

A: You can place the scanner anywhere within the network to scan any device that has layer 3 (L3) reachability. If the scanner can ping a device, it can scan that device. This includes off-site devices that are connected to the customer network through VPN.

Q: Who installs the scanner?

A: An Arctic Wolf employee and your IT staff install the scanner, depending on whether the customer chooses the virtual machine (VM) or physical scanner.

Q: Who maintains the scanner?

A: Arctic Wolf owns the scanner hardware or VM software instance provided to enable network discovery of threats and vulnerabilities. Therefore, Arctic Wolf maintains scanner service, including regular software updates and scanner warranty.

Q: How long does the hardware scanner installation take?

A: The physical installation takes minutes. To physically install the hardware scanner, you need to rack mount the scanner, and connect an Ethernet cable and power cord.

Once powered on, the scanner connects to Arctic Wolf servers within minutes.

Q: What are the physical space and power requirements of the hardware scanner?

A: The physical scanner hardware is a 1RU rack-mountable server with these dimensions in inches: 1.7 high x 16.8 wide x 14.0 deep. A 200-W, low-noise AC power supply with power factor correction (PFC) powers the scanner.

Q: Does the physical scanner support scanning multiple non-routable networks?

A: No, even though the physical scanner has multiple hardware network ports, the software is only configured to allow one primary network, or one network interface card (NIC). Multiple physical, non-routable networks are not supported because that configuration would cause the scanner itself to become a bridge between networks that are otherwise wholly separated, which is a violation of secure design principles.

Q: Do I need to configure the scanner?

A: The scanner can search for hosts on its network and begin scanning without configuration. You can also easily configure the scanner to scan or ignore any other routable host(s) or network(s), if desired.

Q: Do I need to open a port in the firewall for the scanner?

A: The scanner, both physical and virtual, communicates to the Arctic Wolf cloud infrastructure. We recommend that you create a defined outbound security rule from the scanner IP address to all necessary Arctic Wolf scanner IP addresses to ensure proper functionality. To see the complete list of IP addresses that you must allowlist, go to the Arctic Wolf Unified Portal, and then click Help > Allowlist Requirements. The IP addresses that must be allowlisted are listed under Scanners.

Q: Can I have multiple scanners for different parts of my network?

A: Yes, you can deploy multiple scanners to scan separate parts of your network, such as a co-lo or remote office which do not have direct connectivity, or you otherwise do not want to scan from the location of the main Ssanner.

Q: Can we configure our own NTP server for the scanner?

A: No, you cannot configure your own NTP server for the scanner. The scanner is configured to reach out to a pool of global, publicly available NTP servers. This is to ensure consistency in case of localized issues.

Q: What virtual environments are supported for the virtual scanner?

A: See Managed Risk Scanner Installation and Configuration Guide for all requirements.

Q: What kind of impact does the scanner have on the network and systems?

A: The network scanner primarily uses two tools to detect hosts and conduct vulnerability scans:

• Nmap — Very lightweight, sending only Internet Control Message Protocol (ICMP) and synchronize (SYN) packets for port scanning.
• OpenVAS — Also lightweight, typically sending and receiving <400 kB/sec of bandwidth on a typical network. Depending on the hosts that are scanned and what services they are running, occasional bursts of bandwidth to ~1 MB/sec may occur.

The actual impact of processing on the target systems is typically negligible. Some older systems, such as consumer-grade printers or network Internet-of-Things (IoT) devices, may have denial of service vulnerabilities that are revealed when scanned.

Q: Can endpoint detection and response solutions interfere with the scanner?

A: Yes. We recommend adding an exception for the scanner IP address to your endpoint detection and response (EDR) solution.

Scanner operation FAQs

Q: What tests does the scanner perform?

A: The scanner runs network vulnerability tests (NVTs) that provide:

• Remote version detection — The scanner connects to the host services and collects self-reported version information, to verify if hosts are using versions with known vulnerabilities.

  Notes:

  • These NVTs may miss self-applied patches without version numbers.
  • When services are locked down or otherwise configured not to self-report versions, the scanner may not detect these vulnerabilities.

• Crafted packet and response check — The scanner sends a specific series of packets that test if a vulnerability exists based on the response from the host.

• Credentialed detection — If configured, the scanner connects using customer-supplied credentials to obtain a list of installed software, and then the version check NVTs run against that list.

  Tip: This detection can find vulnerabilities that are not remotely exploitable, such as an Adobe Acrobat vulnerability.

• Weak or default password checking — Services that have a sign-in prompt, such as SSH or web pages, or services that collect credentials as part of protocol, like SMB, are tested against default or weak passwords, like password.

  Note: These scans can negatively impact services with lockout policies, so you may need to disable these types of scans on those devices.

Q: What does the scanner do during a scan?

A: Using the provided schedules, the scanner gets the list of targets to look for. Using the list of targets and the data from the DenyList, it attempts to determine if relevant machines are online by sending out Address Resolution Protocol (ARP), Internet Control Message Protocol (ICMP), and Transmission Control Protocol (TCP) packets and monitoring for any responses.

In almost all cases, the scanner runs a full scan that:

• Fingerprints web server software

• Analyzes HTTP headers for security misconfiguration

• Checks the security of HTTP cookies

• Checks the SSL certificate of the server

• Checks if known vulnerabilities are affecting server software

• Analyzes robots.txt for interesting URLs, such as /admin or other restricted pages

• Checks whether a client access file exists and if it contains a wildcard entry such as clientaccesspolicy.xml or crossdomain.xml

• Discovers server configuration problems such as directory listing

• Crawls websites

• Checks for SQL injection

• Checks for cross-site scripting

• Checks for local file inclusion and remote file inclusion

• Checks for operating system (OS) command injection

• Checks for outdated JavaScript libraries

• Finds administrative pages

• Checks for sensitive files such as archives, backups, certificates, or key stores, based on hostname and some common words

• Attempts to find interesting files or functionality, such as restriction or permission concerns

• Checks for information disclosure issues

• Checks mail servers for SMTP problems, including mail relay

Q: What kind of devices does the scanner scan?

A: The scanner can scan all device types on a network, including networking gear like switches and routers, printers, cameras, phones, and so on. However, scanning some devices can cause unintended behaviours, including significant issues to production environments if the scanner is configured to scan specific devices. Therefore, we recommend scanning only workstations and servers.

Here are some devices to avoid scanning:

• Printers, especially large scale printers
• Medical devices
• Internet-of-Things (IOT) devices
• Scanners
• VoIP phones
• Uninterruptible Power Supplies (UPSs)
• Mainframes
• Small network appliances
• Old devices that likely were not built to handle frequent scanning activity
• ESXi servers — Scanning these servers may lock you out and force you to restart their mgmt service.

Q: Does the scanner scan over IPv6 networks?

A: No, the scanner does not support scanning over IPv6 networks.

Q: Does the scanner exploit found vulnerabilities?

A: These are the types of network tests that the scanner runs:

• Host identification tests — ICMP and TCP SYN packets are sent to see if a specific host is connected to the network and responding to basic network connectivity checks.

• Service detection tests — TCP SYN packets are sent to detect what services are responding on which ports.

• Service version tests — The tests connect to a service on the host and determine the version of the service that is running, if possible. Any vulnerabilities for that specific version are checked against a database of known vulnerabilities and matches are reported.

• Exploit tests — The tests connect to a service, wait for a response, and then use that response to send a specifically-crafted packet to determine if a particular vulnerability is exploitable.

• Default credential tests — The tests connect to a service and attempt to login using known and/or default credentials for that service.

Q: How resource-intensive is the scan on the target machine?

A: Managed Risk scans have a very low impact. Users should not notice any impact on the target machine during scanning.

Q: Should I stagger scan times based on location?

A: You can configure scans based on your preference, including location. You may prefer to perform workstation scanning during the day and server scanning overnight. Scans always run in the order that they are listed on the Risk Dashboard. See Risk Dashboard User Guide for more information.

Q: When is continuous scanning applicable or preferred?

A: Continuous scanning enables continuous visibility and the immediate discovery of new devices and vulnerabilities that enter the network.

Continuous scanning is applicable to IVA scanning and host-based scanning, and is a preferred method because it provides insight that point-in-time vulnerability scans do not. Specifically, things happen in between those point-in-time scans that are missed if you are not continuously scanning.

Q: How often are IVA discovery scans run?

A: Nmap scans start five minutes after the previous Nmap scan completes. Precise timing depends on how long it takes for the scan to complete. If Nmap scans take 60 seconds to complete, they would run every six minutes (5 + 1 minutes). If it is a complex network and the Nmap scan takes 15 minutes to run, the Nmap scans would run every 20 minutes (5 + 15 minutes).

Q: Are there best practices for scan schedules?

A: We suggest starting the scans when a member of your team is available. That way, you can add devices to the DenyList or turn off scanning if a host reacts poorly to being scanned. Scanning schedules should help prevent devices from going offline or prevent scanners from overwhelming devices with HTTP requests during business hours.

Q: How long does a typical scan take per device?

A: The scan can take up to an hour to complete but is usually faster. Scan time depends on the number of open ports and network vulnerability tests (NVTs) that the scan runs against the host. By default, six hosts can be scanned at the same time.

Q: How should I configure the scanning schedule?

A: You should only configure private internal IP addresses for the scanner to scan. Do not add anything outside of the ranges listed here: https://en.wikipedia.org/wiki/Private_network.

We recommend:

• Scanning subnet ranges no larger than /24. Scanning larger subnet ranges may not complete in a reasonable timeframe.
• Limiting the number of target IPs scanned to 2048 or less.
• Using a single scanner per collision domain.

With the assumption that each scan takes about 16 minutes to complete per device and with 6 hosts/devices scanned by scanner at same time, this table provides estimates for how long it takes to scan a number of hosts:

Total hosts	Minutes to scan	Hours to scan
1	16	0.3
2	16	0.3
4	16	0.3
8	32	0.5
16	48	0.8
32	96	1.6
64	176	2.9
128	352	5.9
256	688	11.5
512	1376	22.9
1024	2736	45.6

Q: What is the difference between the default discovery scans, like Nmap, and a ping-only scan?

A: The default Nmap scan is used to find what hosts exist, which we should scan for vulnerabilities. The tests performed include:

• Address Resolution Protocol (ARP) scan

• Internet Control Message Protocol (ICMP) echo

• ICMP timestamp

• Transmission Control Protocol (TCP) acknowledge (ACK) on port 80

• TCP synchronize (SYN) on port 443

• TCP SYN on more than 1,000 ports

For more information about ICMP echo requests and the Only ping the target toggle, see Only ping the target toggle.

Q: Does the scanner scan for or detect the SSL/TLS versions that a website supports?

A: The scanner looks for weak TLS ciphers. It does not look at SSL registry information or test against failback methods.

Q: Why is the scanner failing to resolve a host name?

A: The scanner does not perform asset profiling, including host name resolution if:

• The host was not detected during the identification phase.
• The host is on the DenyList for the scanner.

If you are seeing continued failures to resolve the name for a visible host, contact Arctic Wolf so that we can attempt manual tests on the scanner.

IVA scanning FAQs

Q: Does the IVA Scanner scan for common passwords like “admin” or “password” to see if any devices have default or easily guessable passwords on them?

A: There is an option on the IVA Scanner to perform brute-force scans, where common or default usernames and passwords are attempted. We limit the number of passwords attempted to the most common ones, and tailor the list based on the type of device detected to limit causing account lockouts. Additionally, Managed Risk (MR) performs Account Takeover (ATO) scans to identify instances of passwords, credentials, or other personally identifiable information (PII) that were exposed to malicious actors.

Q: If scheduled scans are configured, why are host identification scans occurring outside of the schedule?

A: The IVA Scanner maintains an active list of all targets and decides the targets and order for scanning during the scheduled vulnerability scan, based on the latest results. Host identification scanning, or Nmap scanning, is permitted outside of the vulnerability scanning window so that it does not limit the time remaining in the scheduled window for vulnerability scans. All other scan types occur within the schedule.

Q: How are the credentials that are used in credential scanning stored?

A: When a scanner first comes online and registers with our system, it generates a unique public/private cryptographic key pair using RSA with a 4096-bit key. Part of the registration process for the new scanner is to publish the public component of this key pair to our servers. The private key is never transmitted off of the scanner.

When a credential is added through the Risk Dashboard for credentialed scanning, the data is divided into public and private fields. Public fields include things such as the hosts that a given credential is for, the display name of the credential that is not the username, and a comment for easy viewing on the Risk Dashboard. Private fields include usernames, passwords, certificates, keys, and any information that could be used as a component of the actual credential.

The private fields are encrypted with a unique AES 256 key, or session key, which is in turn encrypted with the public key of a target scanner. This encrypted data package is then paired with the public fields and stored in our database. A copy of this data is sent to the target scanner over a secure channel that again uses unique AES 256 session keys secured with the scanner public key.

The public information is stored in the database for use with the Risk Dashboard, and the private information is stored for re-publishing to the scanner if the scanner ever requests it. Once stored in the database, there is no way for any device other than the scanner to read the private fields of a credential, and they cannot be recovered or moved to another scanner.

When the scanner receives the encrypted credential message, the message is stored to disk using the existing encryption before it is decrypted, and then it is decrypted only as required during use. It is never stored on disk in a decrypted form.

Q: Does vulnerability scanning work if asset identification scanning is disabled?

A: No, you must enable asset identification scanning to perform vulnerability scanning. You can make these adjustments on the Scanner Config page of the Risk Dashboard. See Risk Dashboard User Guide for more information.

Q: How long does it take to scan my environment with continuous scanning?

A: Scanner performance metrics vary depending on your environment. If you are using a vScanner, the allocated resources can also affect sensor performance. However, as a rough guideline, the Arctic Wolf scanner can scan approximately 540 devices in a 24-hour period.

Q: What happens if a scan takes longer than the scan window allots?

A: If a scan is limited to a relatively short scan window, a scan may take longer than the defined window to complete. Since a scan can range from 2–200 minutes, the scanner does not stop scans at the end of a scheduled window to prevent a situation where some longer-running scans would never complete.

For example, if you set a 60-minute window and a host would take 70 minutes to scan, the scan could not complete without exceeding the window. To avoid this, the schedules define when a scan may start, relying on the fact that the majority of scans take only 5–15 minutes to complete.

Q: Can I scan AWS or other cloud-hosted devices?

A: Various cloud providers have different policies around when and if vulnerability assessments are allowed according to their respective Acceptable Use Policies (AUPs):

• AWS — AWS has a strict AUPs around vulnerability scanning, but you can deploy a vScanner for AWS to scan AWS resources. See Install a vScanner in AWS for steps.
• Digital Ocean — Digital Ocean has lightweight AUPs but we highly recommend checking with Digital Ocean to prevent any unintentional service interruptions.
• Others — Discuss and/or check with the appropriate cloud hosting provider on their AUP and vulnerability assessment.

Q: Can we schedule IVA scans of devices or IP addresses on a daily, monthly, or quarterly basis?

A: You can schedule IVA scans to run monthly, weekly, daily, or continuously. This frequency is configurable on a network-by-network or host-by-host basis.

Q: What is the underlying technology used for IVA scanning?

A: OpenVas is the underlying technology used for IVA scanning.

EVA scanning FAQs

Q: How many ports are scanned during an EVA scan?

A: The Nmap or EVA scan uses the top 1,000 common ports. See Nmap Network Scanning Overview on the Nmap website for more information.

Q: How does the EVA Scanner determine if a host is online before performing a vulnerability scan?

A: The EVA Scanner uses the results of an initial Nmap scan confirm that we received port information, even if the ports are reportedly closed, and then proceeds with the EVA scan.

Q: How often are EVA discovery scans run?

A: Nmap discovery scans run before every scan, which occur monthly by default, but can also be requested.

Q: Can we schedule EVA scans of devices or IP addresses on a daily, monthly, or quarterly basis?

A: By default, we run EVA scans on a monthly basis. You can adjust the frequency of EVA scans to weekly, but we do not recommend this approach because it increases the risk of firewall bans from generating too much noise.

Q: What are the EVA port states?

A: The table below describes the port states. See What is Port Scanning? for more information.

Port state	Description
open	The application is actively accepting TCP queries on this port.
closed	The port is accessible but there is no application listening on it.
filtered	We cannot determine whether the port is open because packet filtering prevents probes from reaching the port. This could be due to a firewall, router rules, or host-based firewall software.
unknown	We are unable to determine if the port is open, closed, or filtered.

Scanner troubleshooting FAQs

Q: Why does the scanner show results for itself in the Risk Dashboard?

A: If the scanner IP address is not added to the AllowList on the Scanner Config page of the Risk Dashboard, the scanner IP address can appear in scan results in the Risk Dashboard. To see the complete list of IP addresses that you must allowlist, go to the Arctic Wolf Unified Portal, and then click Help > Allowlist Requirements. The IP addresses that must be allowlisted are listed under Scanners.

Q: Why did I see a bandwidth spike during a scan?

A: Spikes in bandwidth usage may be related to:

• Webservers with a large 404 page — A webserver configured to use a custom 404 page, especially if it contains images, can often be large. The scanner checks for many URLs on webservers that do not exist and a large 404 page transmitted in response can generate large spikes in bandwidth.

• Misconfigured and/or poorly behaving hosts — Some services may immediately respond to an initial connection with a large volume of unsolicited data, generating a spike in bandwidth.

• Stateful east-west firewalls — Networks where Nmap scans travel through a firewall need to be configured to handle the Nmap traffic, or have a separate risks scanner deployed in the network segments. See IVA User Guide for more details.

See also

• Managed Risk Scanner Installation and Configuration Guide
• Risk Dashboard User Guide