RDP NTLM Info Fingerprinting
RDP with CredSSP (NLA) often leaks useful identity and OS details during the NTLM handshake before any real login. This is fast signal for domain context, naming, and rough Windows build without creds.
Nmap rdp-ntlm-info
Run it directly:
If you’re scanning multiple hosts, keep it quiet and output for parsing:
What good output looks like
Expect fields like NetBIOS and DNS naming plus a product version:
| rdp-ntlm-info:
| Target_Name: CONTOSO
| NetBIOS_Domain_Name: CONTOSO
| NetBIOS_Computer_Name: WIN10-WS01
| DNS_Domain_Name: contoso.local
| DNS_Computer_Name: win10-ws01.contoso.local
| Product_Version: 10.0.19045
|_ System_Time: 2026-01-19T10:12:03+00:00
How to use it
DNS_Domain_Name / Target_Name present: treat it as domain-joined until proven otherwise. Set
$DOMAINfrom this and align user spraying formats and AD targeting — see RDP Brute Force and Password Spray.DNS_Computer_Name / NetBIOS_Computer_Name present: you’ve got a reliable hostname for pivoting into DNS, SMB, LDAP, and certificate-based targeting.
Product_Version present: prioritize older-looking builds for deeper vuln checks, and don’t waste time guessing OS family.
When rdp-ntlm-info returns nothing
This usually means CredSSP isn’t in play, the service isn’t Windows RDP, or the endpoint is doing something odd with negotiation.
Confirm the port really speaks RDP:
If you still need identity hints, try pulling the server cert via a client handshake (you’ll often get a CN/SAN with the host naming pattern):
If you don’t have creds, you can still try with empty values just to trigger negotiation and see what it prints before auth fails:
What you’re looking for:
Any displayed server name or certificate subject that gives you a hostname pattern.
Clear errors about required security modes, which changes how you approach follow-on enumeration.
Fast TCP sanity check
This is only for “is something listening”, not fingerprinting:
If it connects, treat it as “open”. Don’t expect a readable banner.
References
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rdp-ntlm-info NSE scriptnmap.org/nsedoc/scripts/rdp-ntlm-info.html (opens in new tab)
Script behavior and returned fields for NTLM-based RDP info disclosure
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