1 files changed, 186 insertions, 0 deletions
diff --git a/scripts/smtp-ntlm-info.nse b/scripts/smtp-ntlm-info.nse
new file mode 100644
index 0000000..b331870
--- /dev/null
+++ b/scripts/smtp-ntlm-info.nse
@@ -0,0 +1,186 @@
+local datetime = require "datetime"
+local os = require "os"
+local smtp = require "smtp"
+local shortport = require "shortport"
+local stdnse = require "stdnse"
+local base64 = require "base64"
+local smbauth = require "smbauth"
+local string = require "string"
+
+
+description = [[
+This script enumerates information from remote SMTP services with NTLM
+authentication enabled.
+
+Sending a SMTP NTLM authentication request with null credentials will
+cause the remote service to respond with a NTLMSSP message disclosing
+information to include NetBIOS, DNS, and OS build version.
+]]
+
+
+---
+-- @usage
+-- nmap -p 25,465,587 --script smtp-ntlm-info --script-args smtp-ntlm-info.domain=domain.com <target>
+--
+-- @output
+-- 25/tcp   open     smtp
+-- | smtp-ntlm-info:
+-- |   Target_Name: ACTIVESMTP
+-- |   NetBIOS_Domain_Name: ACTIVESMTP
+-- |   NetBIOS_Computer_Name: SMTP-TEST2
+-- |   DNS_Domain_Name: somedomain.com
+-- |   DNS_Computer_Name: smtp-test2.somedomain.com
+-- |   DNS_Tree_Name: somedomain.com
+-- |_  Product_Version: 6.1.7601
+--
+--@xmloutput
+-- <elem key="Target_Name">ACTIVESMTP</elem>
+-- <elem key="NetBIOS_Domain_Name">ACTIVESMTP</elem>
+-- <elem key="NetBIOS_Computer_Name">SMTP-TEST2</elem>
+-- <elem key="DNS_Domain_Name">somedomain.com</elem>
+-- <elem key="DNS_Computer_Name">smtp-test2.somedomain.com</elem>
+-- <elem key="DNS_Tree_Name">somedomain.com</elem>
+-- <elem key="Product_Version">6.1.7601</elem>
+
+
+author = "Justin Cacak"
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+categories = {"default", "discovery", "safe"}
+
+
+local ntlm_auth_blob = base64.enc( select(2,
+  smbauth.get_security_blob(nil, nil, nil, nil, nil, nil, nil,
+    0x00000001 + -- Negotiate Unicode
+    0x00000002 + -- Negotiate OEM strings
+    0x00000004 + -- Request Target
+    0x00000200 + -- Negotiate NTLM
+    0x00008000 + -- Negotiate Always Sign
+    0x00080000 + -- Negotiate NTLM2 Key
+    0x20000000 + -- Negotiate 128
+    0x80000000 -- Negotiate 56
+    ))
+  )
+
+portrule = shortport.port_or_service({ 25, 465, 587 }, { "smtp", "smtps", "submission" })
+
+local function do_connect(host, port, domain)
+  local options = {
+    recv_before = true,
+    ssl = true,
+  }
+
+  local socket, response = smtp.connect(host, port, options)
+  if not socket then
+    return
+  end
+
+  -- Required to send EHLO
+  local status, response = smtp.ehlo(socket, domain)
+  if not status then
+    return
+  end
+
+  return socket
+end
+
+action = function(host, port)
+
+  local output = stdnse.output_table()
+
+  -- Select domain name.  Typically has no implication for this purpose.
+  local domain = stdnse.get_script_args(SCRIPT_NAME .. ".domain") or smtp.get_domain(host)
+
+  local socket = do_connect(host, port, domain)
+  if not socket then
+    return nil
+  end
+
+  -- Per RFC, do not attempt to upgrade to a TLS connection if already over TLS
+  if not shortport.ssl(host, port) then
+    -- After EHLO, attempt to upgrade to a TLS connection (may not be advertised)
+    -- Various implementations *require* this before accepting authentication requests
+    local status, response = smtp.starttls(socket)
+    if status then
+      -- Read line after upgrading the connection or timeout trying.
+      -- This may induce a delay, however, appears required under rare conditions
+      -- since reconnect_ssl does not support recv_before.
+      -- -- commenting this out, not needed in testing, but may crop up sometime.
+      --status, response = socket:receive_lines(1)
+      -- Per RFC, must EHLO again after connection upgrade
+      status, response = smtp.ehlo(socket, domain)
+    else
+      -- STARTTLS failed, which means smtp.lua sent QUIT and shut down the
+      -- connection. Try again without SSL
+      socket = do_connect(host, port, domain)
+    end
+  end
+
+  socket:send("AUTH NTLM\r\n")
+  local status, response = socket:receive()
+  if not response then
+    return
+  end
+
+  socket:send(ntlm_auth_blob .. "\r\n")
+  status, response = socket:receive()
+  if not response then
+    return
+  end
+  local recvtime = os.time()
+
+  socket:close()
+
+  -- Continue only if a 334 response code is returned
+  local response_decoded = string.match(response, "^334 (.*)")
+  if not response_decoded then
+    return
+  end
+
+  response_decoded = base64.dec(response_decoded)
+
+  -- Continue only if NTLMSSP response is returned
+  if not string.match(response_decoded, "^NTLMSSP") then
+    return nil
+  end
+
+  local ntlm_decoded = smbauth.get_host_info_from_security_blob(response_decoded)
+
+  if ntlm_decoded.timestamp and ntlm_decoded.timestamp > 0 then
+    stdnse.debug1("timestamp is %s", ntlm_decoded.timestamp)
+    -- 64-bit number of 100ns clicks since 1/1/1601
+    local unixstamp = ntlm_decoded.timestamp // 10000000 - 11644473600
+    datetime.record_skew(host, unixstamp, recvtime)
+  end
+
+  -- Target Name will always be returned under any implementation
+  output.Target_Name = ntlm_decoded.target_realm
+
+  -- Display information returned & ignore responses with null values
+  if ntlm_decoded.netbios_domain_name and #ntlm_decoded.netbios_domain_name > 0 then
+    output.NetBIOS_Domain_Name = ntlm_decoded.netbios_domain_name
+  end
+
+  if ntlm_decoded.netbios_computer_name and #ntlm_decoded.netbios_computer_name > 0 then
+    output.NetBIOS_Computer_Name = ntlm_decoded.netbios_computer_name
+  end
+
+  if ntlm_decoded.dns_domain_name and #ntlm_decoded.dns_domain_name > 0 then
+    output.DNS_Domain_Name = ntlm_decoded.dns_domain_name
+  end
+
+  if ntlm_decoded.fqdn and #ntlm_decoded.fqdn > 0 then
+    output.DNS_Computer_Name = ntlm_decoded.fqdn
+  end
+
+  if ntlm_decoded.dns_forest_name and #ntlm_decoded.dns_forest_name > 0 then
+    output.DNS_Tree_Name = ntlm_decoded.dns_forest_name
+  end
+
+  if ntlm_decoded.os_major_version then
+    output.Product_Version = string.format("%d.%d.%d",
+      ntlm_decoded.os_major_version, ntlm_decoded.os_minor_version, ntlm_decoded.os_build)
+  end
+
+  return output
+
+end