1 files changed, 29 insertions, 0 deletions
diff --git a/scripts/smtp-strangeport.nse b/scripts/smtp-strangeport.nse
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+++ b/scripts/smtp-strangeport.nse
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+description = [[
+Checks if SMTP is running on a non-standard port.
+
+This may indicate that crackers or script kiddies have set up a backdoor on the
+system to send spam or control the machine.
+]]
+
+---
+-- @output
+-- 22/tcp  open   smtp
+-- |_ smtp-strangeport: Mail server on unusual port: possible malware
+
+author = "Diman Todorov"
+
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+
+categories = {"malware", "safe"}
+
+portrule = function(host, port)
+  return port.service == "smtp" and
+    port.number ~= 25 and port.number ~= 465 and port.number ~= 587
+    and port.protocol == "tcp"
+    and port.state == "open"
+end
+
+action = function()
+  return "Mail server on unusual port: possible malware"
+end
+