A slightly improved version of nmap's http-screenshot.nse

http-screenshot.nse

local shortport = require "shortport"
local stdnse = require "stdnse"

description = [[

Gets a screenshot from a Web service using webshot.js, a nodejs/puppeteer script.

It can be used with IVRE.

]]

author = "Javier Gil <javier.gilmaestro@telefonica.com>"
license = "GPLv3"
categories = {"discovery", "safe", "screenshot"}

---
-- @usage
-- nmap -n -p 80 --script http-screenshot www.google.com
--
-- @args http-screenshot.vhost the vhost to use (default: use the
--       provided hostname or IP address)
-- @args http-screenshot.timeout timeout for the webshot.js script
--       (default: 300s)
--
-- @output
-- PORT   STATE SERVICE
-- 80/tcp open  http
-- |_http-screenshot: Saved to screenshot-173.194.45.82-www.google.com-80.jpg

portrule = shortport.http

local function get_hostname(host)
  local arg = stdnse.get_script_args(SCRIPT_NAME .. '.vhost')
  return arg or host.targetname or host.ip
end

action = function(host, port)
  local fname, strport, cmd
  
  local timeout = tonumber(stdnse.get_script_args(SCRIPT_NAME .. '.timeout')) or 300

  local ssl = port.version.service_tunnel == "ssl" or (
    port.version.sevice_name == nil and port.service:match("https") ~= nil
  )

  local port = port.number
  
  local hostname = get_hostname(host)

  if hostname == host.ip then
    fname = ("screenshot-%s-%d.jpg"):format(host.ip, port)
  else
    fname = ("screenshot-%s-%s-%d.jpg"):format(host.ip, hostname, port)
  end

  if (port == 80 and not ssl) or (port == 443 and ssl) then
    strport = ""
  else
    strport = (":%d"):format(port)
  end

  local url = ("%s://%s%s"):format(ssl and "https" or "http", hostname, strport)

  cmd = ("webshot.js %s %s"):format(url, fname)
  os.execute("timeout " .. timeout .. " " .. cmd) 

  return (os.rename(fname, fname)
	    and ("Saved to %s"):format(fname)
	    or "Failed")
end

webshot.js

#!/usr/bin/node

const puppeteer = require('puppeteer');

const url = process.argv[2];
const filepath = process.argv[3];

console.log("Fetching " + url);
console.log("Saving to " + filepath);

(async () => {
 	const browser = await puppeteer.launch({
		ignoreHTTPSErrors: true,
		defaultViewport: {
			width: 1920,
			height: 981
		}
	});

	const page = await browser.newPage();
	await page.goto(url);
	await page.screenshot({path: filepath, fullPage: true});

	await browser.close();
})().catch((e) => {
	console.log("Failed: " + e);
	process.exit(-1);
});;