The Shadowserver Foundation

Open NetBIOS Scanning Project

If you are looking at this page, then more than likely, you noticed a scan coming from this server across your network and/or poking at NetBIOS.

The Shadowserver Foundation is currently undertaking a project to search for publicly accessible devices that have NetBIOS running and answering Name Resolution queries. The goal of this project is to identify openly accessible NetBIOS services and report them back to the network owners for remediation.

These devices have the potential to be used in UDP amplification attacks and if at all possible, we would like to see these services made un-available to miscreants that would misuse these resources.

Servers that are configured this way have been incorporated into our reports and are being reported on a daily basis.

Information on UDP-based amplification attacks in general can be found in US-CERT alert TA14-017A at: https://www.us-cert.gov/ncas/alerts/TA14-017A

Methodology

We are querying all computers with routable IPv4 addresses that are not firewalled from the internet on port 137/udp with a NetBIOS request for the Name Resolution of the probed IP. We are capturing the response from the NetBIOS service and parsing the result. We intend no harm, but if we are causing problems, please contact us at gro [tod] revfooreswodahs [ta] nacbarssnd

If you would like to test your own device to see if NetBIOS is active, run this command from a windows system: "nbtstat -A [IP]"

Whitelisting

To be removed from this set of scanning you will need to send an email to dnsscan [at] shadowserver [dot] org with the specific CIDR's that you would like to have removed. You will have to be the verifiable owner of these CIDR's and be able to prove that fact. Any address space that is whitelisted will be publicly available here: https://netbiosscan.shadowserver.org/exclude.html

Useful Links

Scan Status

Statistics on current run

Other Statistics

If you would like other statistics and information on historical trends, please take a look at: https://netbiosscan.shadowserver.org/stats/. Otherwise, stats from the most current scan are listed below.


All NetBIOS Servers

All NetBIOS

(Click image to enlarge)

These are the 2.5 million open NetBIOS servers

If you would like to see more regions click here

All NetBIOS Servers

All NetBIOS

(Click image to enlarge)

These are the 2.5 million open NetBIOS servers



If you would like us to not scan your network, please let us know and we will remove your networks from the scan.

Likewise, if you have anymore questions please feel free to send us an email at: gro [tod] revfooreswodahs [ta] nacbarssnd

The Shadowserver Foundation