local _G = require "_G" local io = require "io" local math = require "math" local msrpc = require "msrpc" local nmap = require "nmap" local smb = require "smb" local stdnse = require "stdnse" local string = require "string" local stringaux = require "stringaux" local table = require "table" description = [[ Implements remote process execution similar to the Sysinternals' psexec tool, allowing a user to run a series of programs on a remote machine and read the output. This is great for gathering information about servers, running the same tool on a range of system, or even installing a backdoor on a collection of computers. This script can run commands present on the remote machine, such as ping or tracert, or it can upload a program and run it, such as pwdump6 or a backdoor. Additionally, it can read the program's stdout/stderr and return it to the user (works well with ping, pwdump6, etc), or it can read a file that the process generated (fgdump, for example, generates a file), or it can just start the process and let it run headless (a backdoor might run like this). To use this, a configuration file should be created and edited. Several configuration files are included that you can customize, or you can write your own. This config file is placed in nselib/data/psexec (if you aren't sure where that is, search your system for default.lua), then is passed to Nmap as a script argument (for example, myconfig.lua would be passed as --script-args=config=myconfig. The configuration file consists mainly of a module list. Each module is defined by a lua table, and contains fields for the name of the program, the executable and arguments for the program, and a score of other options. Modules also have an 'upload' field, which determines whether or not the module is to be uploaded. Here is a simple example of how to run

net
localgroup administrators

, which returns a list of users in the "administrators" group (take a look at the examples.lua configuration file for these examples):


  mod = {}
  mod.upload           = false
  mod.name             = "Example 1: Membership of 'administrators'"
  mod.program          = "net.exe"
  mod.args             = "localgroup administrators"
  table.insert(modules, mod)

mod.upload is false, meaning the program should already be present on the remote system (since 'net.exe' is on every version of Windows, this should be the case). mod.name defines the name that the program will have in the output. mod.program and mod.args obviously define which program is going to be run. The output for this script is this:


  |  Example 1: Membership of 'administrators'
  |  | Alias name     administrators
  |  | Comment        Administrators have complete and unrestricted access to the computer/domain
  |  |
  |  | Members
  |  |
  |  | -------------------------------------------------------------------------------
  |  | Administrator
  |  | ron
  |  | test
  |  | The command completed successfully.
  |  |
  |  |_

That works, but it's really ugly. In general, we can use mod.find, mod.replace, mod.remove, and mod.noblank to clean up the output. For this example, we're going to use mod.remove to remove a lot of the useless lines, and mod.noblank to get rid of the blank lines that we don't want:


  mod = {}
  mod.upload           = false
  mod.name             = "Example 2: Membership of 'administrators', cleaned"
  mod.program          = "net.exe"
  mod.args             = "localgroup administrators"
  mod.remove           = {"The command completed", "%-%-%-%-%-%-%-%-%-%-%-", "Members", "Alias name", "Comment"}
  mod.noblank          = true
  table.insert(modules, mod)

We can see that the output is now much cleaner:


|  Example 2: Membership of 'administrators', cleaned
|  | Administrator
|  | ron
|  |_test

For our next command, we're going to run Windows' ipconfig.exe, which outputs a significant amount of unnecessary information, and what we do want isn't formatted very nicely. All we want is the IP address and MAC address, and we get it using mod.find and mod.replace:


  mod = {}
  mod.upload           = false
  mod.name             = "Example 3: IP Address and MAC Address"
  mod.program          = "ipconfig.exe"
  mod.args             = "/all"
  mod.maxtime          = 1
  mod.find             = {"IP Address", "Physical Address", "Ethernet adapter"}
  mod.replace          = {{"%. ", ""}, {"-", ":"}, {"Physical Address", "MAC Address"}}
  table.insert(modules, mod)

This module searches for lines that contain "IP Address", "Physical Address", or "Ethernet adapter". In these lines, a ". " is replaced with nothing, a "-" is replaced with a colon, and the term "Physical Address" is replaced with "MAC Address" (arguably unnecessary). Run ipconfig /all yourself to see what we start with, but here's the final output:


|  Example 3: IP Address and MAC Address
|  | Ethernet adapter Local Area Connection:
|  |    MAC Address: 00:0C:29:12:E6:DB
|  |_   IP Address: 192.168.1.21|  Example 3: IP Address and MAC Address

Another interesting part of this script is that variables can be used in any script fields. There are two types of variables: built-in and user-supplied. Built-in variables can be anything found in the config table, most of which are listed below. The more interesting ones are: * $lhost: The address of the scanner * $rhost: The address being scanned * $path: The path where the scripts are uploaded * $share: The share where the script was uploaded User-supplied arguments are given on the commandline, and can be controlled by mod.req_args in the configuration file. Arguments are given by the user in --script-args; for example, to set $host to '1.2.3.4', the user would pass in --script-args=host=1.2.3.4. To ensure the user passes in the host variable, mod.req_args would be set to {'host'}. Here is a module that pings the local ip address:


  mod = {}
  mod.upload           = false
  mod.name             = "Example 4: Can the host ping our address?"
  mod.program          = "ping.exe"
  mod.args             = "$lhost"
  mod.remove           = {"statistics", "Packet", "Approximate", "Minimum"}
  mod.noblank          = true
  mod.env              = "SystemRoot=c:\\WINDOWS"
  table.insert(modules, mod)

And the output:


|  Example 4: Can the host ping our address?
|  | Pinging 192.168.1.100 with 32 bytes of data:
|  | Reply from 192.168.1.100: bytes=32 time<1ms TTL=64
|  | Reply from 192.168.1.100: bytes=32 time<1ms TTL=64
|  | Reply from 192.168.1.100: bytes=32 time<1ms TTL=64
|  |_Reply from 192.168.1.100: bytes=32 time<1ms TTL=64

And this module pings an arbitrary address that the user is expected to give:


  mod = {}
  mod.upload           = false
  mod.name             = "Example 5: Can the host ping $host?"
  mod.program          = "ping.exe"
  mod.args             = "$host"
  mod.remove           = {"statistics", "Packet", "Approximate", "Minimum"}
  mod.noblank          = true
  mod.env              = "SystemRoot=c:\\WINDOWS"
  mod.req_args         = {'host'}
  table.insert(modules, mod)

And the output (note that we had to up the timeout so this would complete; we'll talk about override values later):


$ ./nmap -n -d -p445 --script=smb-psexec --script-args=smbuser=test,smbpass=test,config=examples,host=1.2.3.4 192.168.1.21
[...]
|  Example 5: Can the host ping 1.2.3.4?
|  | Pinging 1.2.3.4 with 32 bytes of data:
|  | Request timed out.
|  | Request timed out.
|  | Request timed out.
|  |_Request timed out.

For the final example, we'll use the upload command to upload fgdump.exe, run it, download its output file, and clean up its logfile. You'll have to put fgdump.exe in the same folder as the script for this to work:


  mod = {}
  mod.upload           = true
  mod.name             = "Example 6: FgDump"
  mod.program          = "fgdump.exe"
  mod.args             = "-c -l fgdump.log"
  mod.url              = "http://www.foofus.net/fizzgig/fgdump/"
  mod.tempfiles        = {"fgdump.log"}
  mod.outfile          = "127.0.0.1.pwdump"
  table.insert(modules, mod)

The -l argument for fgdump supplies the name of the logfile. That file is listed in the mod.tempfiles field. What, exactly, does mod.tempfiles do? It simply gives the service a list of files to delete while cleaning up. The cleanup process will be discussed later. mod.url is displayed to the user if mod.program isn't found in nselib/data/psexec/. And finally, mod.outfile is the file that is downloaded from the system. This is required because fgdump writes to an output file instead of to stdout (pwdump6, for example, doesn't require mod.outfile. Now that we've seen a few possible combinations of fields, I present a complete list of all fields available and what each of them do. Many of them will be familiar, but there are a few that aren't discussed in the examples: * upload (boolean) true if it's a local file to upload, false if it's already on the host machine. If upload is true, program has to be in nselib/data/psexec. * name (string) The name to display above the output. If this isn't given, program .. args are used. * program (string) If upload is false, the name (fully qualified or relative) of the program on the remote system; if upload is true, the name of the local file that will be uploaded (stored in nselib/data/psexec). * args (string) Arguments to pass to the process. * env (string) Environmental variables to pass to the process, as name=value pairs, delimited, per Microsoft's spec, by NULL characters (string.char(0)). * maxtime (integer) The approximate amount of time to wait for this process to complete. The total timeout for the script before it gives up waiting for a response is the total of all maxtime fields. * extrafiles (string[]) Extra file(s) to upload before running the program. These will not be renamed (because, presumably, if they are then the program won't be able to find them), but they will be marked as hidden/system/etc. This may cause a race condition if multiple people are doing this at once, but there isn't much we can do. The files are also deleted afterwards as tempfiles would be. The files have to be in the same directory as programs (nselib/data/psexec), but the program doesn't necessarily need to be an uploaded one. * tempfiles (string[]) A list of temporary files that the process is known to create (if the process does create files, using this field is recommended because it helps avoid making a mess on the remote system). * find (string[]) Only display lines that contain the given string(s) (for example, if you're searching for a line that contains "IP Address", set this to

{'IP
                    Address'}

. This allows Lua-style patterns, see: http://lua-users.org/wiki/PatternsTutorial (don't forget to escape special characters with a %). Note that this is client-side only; the full output is still returned, the rest is removed while displaying. The line of output only needs to match one of the strings given here. * remove (string[]) Opposite of find; this removes lines containing the given string(s) instead of displaying them. Like find, this is client-side only and uses Lua-style patterns. If remove and find are in conflict, then remove takes priority. * noblank (boolean) Setting this to true removes all blank lines from the output. * replace (table) A table of values to replace in the strings returned. Like find and replace, this is client-side only and uses Lua-style patterns. * headless (boolean) If headless is set to true, the program doesn't return any output; rather, it runs detached from the service so that, when the service ends, the program keeps going. This can be useful for, say, a monitoring program. Or a backdoor, if that's what you're into (a Metasploit payload should work nicely). Not compatible with: find, remove, noblank, replace, maxtime, outfile. * enabled (boolean) Set to false, and optionally set disabled_message, if you don't want a module to run. Alternatively, you can comment out the process. * disabled_message (string) Displayed if the module is disabled. * url (string) A module where the user can download the uploadable file. Displayed if the uploadable file is missing. * outfile (string) If set, the specified file will be returned instead of stdout. * req_args (string[]) An array of arguments that the user must set in --script-args. Any field in the configuration file can contain variables, as discussed. Here are some of the available built-in variables: * $lhost: local IP address as a string. * $lport: local port (meaningless; it'll change by the time the module is uploaded since multiple connections are made). * $rhost: remote IP address as a string. * $rport: remote port. * $lmac: local MAC address as a string in the xx:xx:xx:xx:xx:xx format (note: requires root). * $path: the path where the file will be uploaded to. * $service_name: the name of the service that will be running this program * $service_file: the name of the executable file for the service * $temp_output_file: The (ciphered) file where the programs' output will be written before being renamed to $output_file * $output_file: The final name of the (ciphered) output file. When this file appears, the script downloads it and stops the service * $timeout: The total amount of time the script is going to run before it gives up and stops the process * $share: The share that everything was uploaded to * (script args): Any value passed as a script argument will be replaced (for example, if Nmap is run with --script-args=var3=10, then $var3 in any field will be replaced with 10. See the req_args field above. Script argument values take priority over config values. In addition to modules, the configuration file can also contain overrides. Most of these aren't useful, so I'm not going to go into great detail. Search smb-psexec.nse for any reference to the config table; any value in the config table can be overridden with the overrides table in the module. The most useful value to override is probably timeout. Before and after scripts are run, and when there's an error, a cleanup is performed. in the cleanup, we attempt to stop the remote processes, delete all programs, output files, temporary files, extra files, etc. A lot of effort was put into proper cleanup, since making a mess on remote systems is a bad idea. Now that I've talked at length about how to use this script, I'd like to spend some time talking about how it works. Running a script happens in several stages: 1. An open fileshare is found that we can write to. Finding an open fileshare basically consists of enumerating all shares and seeing which one(s) we have access to. 2. A "service wrapper", and all of the uploadable/extra files, are uploaded. Before they're uploaded, the name of each file is obfuscated. The obfuscation completely renames the file, is unique for each source system, and doesn't change between multiple runs. This obfuscation has the benefit of preventing filenames from overlapping if multiple people are running this against the same computer, and also makes it more difficult to determine their purposes. The reason for keeping them consistent for every run is to make cleanup possible: a random filename, if the script somehow fails, will be left on the system. 3. A new service is created and started. The new service has a random name for the same reason the files do, and points at the 'service wrapper' program that was uploaded. 4. The service runs the processes. One by one, the processes are run and their output is captured. The output is obfuscated using a simple (and highly insecure) xor algorithm, which is designed to prevent casual sniffing (but won't deter intelligent attackers). This data is put into a temporary output file. When all the programs have finished, the file is renamed to the final output file 5. The output file is downloaded, and the cleanup is performced. The file being renamed triggers the final stage of the program, where the data is downloaded and all relevant files are deleted. 6. Output file, now decrypted, is formatted and displayed to the user. And that's how it works! Please post any questions, or suggestions for better modules, to dev@nmap.org. And, as usual, since this tool can be dangerous and can easily be viewed as a malicious tool -- use this responsibly, and don't break any laws with it. Some ideas for later versions (TODO): * Set up a better environment for scripts (PATH, SystemRoot, etc). Without this, a lot of programs (especially ones that deal with network traffic) behave oddly. * Abstract the code required to run remote processes so other scripts can use it more easily (difficult, but will ultimately be well worth it later). (May actually not be possible. There is a lot of overhead and specialized code in this module. We'll see, though.) * Let user specify an output file (per-script) so they can, for example, download binary files (don't think it's worthwhile). * Consider running the external programs in parallel (not sure if the benefits outweigh the drawbacks). * Let the config request the return code from the process instead of the output (not sure if doing this would be worth the effort). * Check multiple shares in a single session to save packets (and see where else we can tighten up the amount of traffic). ]] --- -- @usage -- nmap --script smb-psexec.nse --script-args=smbuser=,smbpass=[,config=] -p445 -- sudo nmap -sU -sS --script smb-psexec.nse --script-args=smbuser=,smbpass=[,config=] -p U:137,T:139 -- -- @output -- Host script results: -- | smb-psexec: -- | | Windows version -- | | |_ Microsoft Windows 2000 [Version 5.00.2195] -- | | IP Address and MAC Address from 'ipconfig.exe' -- | | | Ethernet adapter Local Area Connection 2: -- | | | MAC Address: 00:50:56:A1:24:C2 -- | | | IP Address: 10.0.0.30 -- | | | Ethernet adapter Local Area Connection: -- | | |_ MAC Address: 00:50:56:A1:00:65 -- | | User list from 'net user' -- | | | Administrator TestUser3 Guest -- | | | IUSR_RON-WIN2K-TEST IWAM_RON-WIN2K-TEST nmap -- | | | rontest123 sshd SvcCOPSSH -- | | |_ test1234 Testing TsInternetUser -- | | Membership of 'administrators' from 'net localgroup administrators' -- | | | Administrator -- | | | SvcCOPSSH -- | | | test1234 -- | | |_ Testing -- | | Can the host ping our address? -- | | | Pinging 10.0.0.138 with 32 bytes of data: -- | | |_ Reply from 10.0.0.138: bytes=32 time<10ms TTL=64 -- | | Traceroute back to the scanner -- | | |_ 1 <10 ms <10 ms <10 ms 10.0.0.138 -- | | ARP Cache from arp.exe -- | | | Internet Address Physical Address Type -- | | |_ 10.0.0.138 00-50-56-a1-27-4b dynamic -- | | List of listening and established connections (netstat -an) -- | | | Proto Local Address Foreign Address State -- | | | TCP 0.0.0.0:22 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:25 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:80 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:135 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:443 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:445 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:1025 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:1028 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:1029 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:3389 0.0.0.0:0 LISTENING -- | | | TCP 0.0.0.0:4933 0.0.0.0:0 LISTENING -- | | | TCP 10.0.0.30:139 0.0.0.0:0 LISTENING -- | | | TCP 127.0.0.1:2528 127.0.0.1:2529 ESTABLISHED -- | | | TCP 127.0.0.1:2529 127.0.0.1:2528 ESTABLISHED -- | | | TCP 127.0.0.1:2531 127.0.0.1:2532 ESTABLISHED -- | | | TCP 127.0.0.1:2532 127.0.0.1:2531 ESTABLISHED -- | | | TCP 127.0.0.1:5152 0.0.0.0:0 LISTENING -- | | | TCP 127.0.0.1:5152 127.0.0.1:2530 CLOSE_WAIT -- | | | UDP 0.0.0.0:135 *:* -- | | | UDP 0.0.0.0:445 *:* -- | | | UDP 0.0.0.0:1030 *:* -- | | | UDP 0.0.0.0:3456 *:* -- | | | UDP 10.0.0.30:137 *:* -- | | | UDP 10.0.0.30:138 *:* -- | | | UDP 10.0.0.30:500 *:* -- | | | UDP 10.0.0.30:4500 *:* -- | | |_ UDP 127.0.0.1:1026 *:* -- | | Full routing table from 'netstat -nr' -- | | | =========================================================================== -- | | | Interface List -- | | | 0x1 ........................... MS TCP Loopback interface -- | | | 0x2 ...00 50 56 a1 00 65 ...... VMware Accelerated AMD PCNet Adapter -- | | | 0x1000004 ...00 50 56 a1 24 c2 ...... VMware Accelerated AMD PCNet Adapter -- | | | =========================================================================== -- | | | =========================================================================== -- | | | Active Routes: -- | | | Network Destination Netmask Gateway Interface Metric -- | | | 10.0.0.0 255.255.255.0 10.0.0.30 10.0.0.30 1 -- | | | 10.0.0.30 255.255.255.255 127.0.0.1 127.0.0.1 1 -- | | | 10.255.255.255 255.255.255.255 10.0.0.30 10.0.0.30 1 -- | | | 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1 -- | | | 224.0.0.0 224.0.0.0 10.0.0.30 10.0.0.30 1 -- | | | 255.255.255.255 255.255.255.255 10.0.0.30 2 1 -- | | | =========================================================================== -- | | | Persistent Routes: -- | | | None -- |_ |_ |_ Route Table -- --@args config The config file to use (eg, default). Config files require a .lua extension, and are located in nselib/data/psexec. --@args nohide Don't set the uploaded files to hidden/system/etc. --@args cleanup Set to only clean up any mess we made (leftover files, processes, etc. on the host OS) on a previous run of the script. -- This will attempt to delete the files from every share, not just the first one. This is done to prevent leftover -- files if the OS changes the ordering of the shares (there's no guarantee of shares coming back in any particular -- order) -- Note that cleaning up is still fairly invasive, since it has to re-discover the proper share, connect to it, -- delete files, open the services manager, etc. --@args share Set to override the share used for uploading. This also stops shares from being enumerated, and all other shares -- will be ignored. No checks are done to determine whether or not this is a valid share before using it. Reqires -- sharepath to be set. --@args sharepath The full path to the share (eg, "c:\windows"). This is required when creating a service. --@args time The minimum amount of time, in seconds, to wait for the external module to finish (default: 15) -- --@args nocleanup Set to not clean up at all; this leaves the files on the remote system and the wrapper -- service installed. This is bad in practice, but significantly reduces the network traffic and makes analysis -- easier. --@args nocipher Set to disable the ciphering of the returned text (useful for debugging). --@args key Script uses this value instead of a random encryption key (useful for debugging the crypto). ----------------------------------------------------------------------- author = "Ron Bowes" copyright = "Ron Bowes" license = "Same as Nmap--See https://nmap.org/book/man-legal.html" categories = {"intrusive"} dependencies = {"smb-brute"} -- Where we tell the user to get nmap_service.exe if it's not installed. local NMAP_SERVICE_EXE_DOWNLOAD = "https://nmap.org/psexec/nmap_service.exe" hostrule = function(host) return smb.get_port(host) ~= nil end ---Get the random-ish filenames used by the service. -- --@param host The host table, which the names are based on. --@return Status: true or false. --@return Name of the remote service, or an error message if status is false. --@return Name of the executable file that's run by the service. --@return Name of the temporary output file. --@return Name of the final output file. local function get_service_files(host) local status, service_name, service_file, temp_output_file, output_file -- Get the name of the service status, service_name = smb.get_uniqueish_name(host) if(status == false) then return false, string.format("Error generating service name: %s", service_name) end stdnse.debug1("Generated static service name: %s", service_name) -- Get the name and service's executable file (with a .txt extension for fun) status, service_file = smb.get_uniqueish_name(host, "txt") if(status == false) then return false, string.format("Error generating remote filename: %s", service_file) end stdnse.debug1("Generated static service name: %s", service_name) -- Get the temporary output file status, temp_output_file = smb.get_uniqueish_name(host, "out.tmp") if(status == false) then return false, string.format("Error generating remote filename: %s", temp_output_file) end stdnse.debug1("Generated static service filename: %s", temp_output_file) -- Get the actual output file status, output_file = smb.get_uniqueish_name(host, "out") if(status == false) then return false, string.format("Error generating remote output file: %s", output_file) end stdnse.debug1("Generated static output filename: %s", output_file) -- Return everything return true, service_name, service_file, temp_output_file, output_file end ---Stop/delete the service and delete the service file. -- --@param host The host object. --@param config The table of configuration values. function cleanup(host, config) local status, err -- Add a delay here. For some reason, calling this function too quickly causes SMB to close the connection, -- but even a tiny delay makes that issue go away. stdnse.sleep(.01) -- If the user doesn't want to clean up, don't if(stdnse.get_script_args( "nocleanup" )) then return end stdnse.debug1("Entering cleanup() -- errors here can generally be ignored") -- Try stopping the service status, err = msrpc.service_stop(host, config.service_name) if(status == false) then stdnse.debug1("[cleanup] Couldn't stop service: %s", err) end -- Try deleting the service status, err = msrpc.service_delete(host, config.service_name) if(status == false) then stdnse.debug1("[cleanup] Couldn't delete service: %s", err) end -- Delete the files for _, share in ipairs(config.all_shares) do status, err = smb.file_delete(host, share, config.all_files) end stdnse.debug1("Leaving cleanup()") return true end ---Find the file on the system (checks both Nmap's directories and the current -- directory). -- --@param filename The name of the file. --@param extension The extension of the file (filename without the extension is tried first). --@return The full filename, or nil if it couldn't be found. local function locate_file(filename, extension) stdnse.debug1("Attempting to find file: %s", filename) extension = extension or "" local filename_full = nmap.fetchfile(filename) or nmap.fetchfile(filename .. "." .. extension) if(filename_full == nil) then local psexecfile = "nselib/data/psexec/" .. filename filename_full = nmap.fetchfile(psexecfile) or nmap.fetchfile(psexecfile .. "." .. extension) end -- check for absolute path or relative to current directory if(filename_full == nil) then local f, err = io.open(filename, "rb") if f == nil then stdnse.debug1("Error opening %s: %s", filename, err) f, err = io.open(filename .. "." .. extension, "rb") if f == nil then stdnse.debug1("Error opening %s.%s: %s", filename, extension, err) return nil -- unnecessary, but explicit else f:close() return filename .. "." .. extension end else f:close() return filename end end return filename_full end ---Generate an array of all files that will be uploaded/created, including -- the temporary file and the output file. This is done so the files can -- all be deleted during the cleanup phase. -- --@param config The config table. --@return The array of files. local function get_all_files(config) local files = {config.service_file, config.output_file, config.temp_output_file} for _, mod in ipairs(config.enabled_modules) do -- We're going to delete the module itself table.insert(files, mod.upload_name) -- We're also going to delete any temp files... if(mod.tempfiles) then for _, file in ipairs(mod.tempfiles) do table.insert(files, file) end end -- ... and any extra files we uploaded ,,, if(mod.extrafiles) then for _, file in ipairs(mod.extrafiles) do table.insert(files, file) end end -- ... not to mention the output file if(mod.outfile and mod.outfile ~= "") then table.insert(files, mod.outfile) end end return files end ---Decide which share to use. Unless the user overrides it with the 'share' and 'sharepath' -- arguments, a the first writable share is used. -- --@param host The host object. --@return status true for success, false for failure --@return share The share we're going to use, or an error message. --@return path The path on the remote system that points to the share. --@return shares A list of all shares on the system (used for cleaning up). local function find_share(host) local status, share, path, shares -- Determine which share to use if(nmap.registry.args.share ~= nil) then share = nmap.registry.args.share shares = {share} path = nmap.registry.args.sharepath if(path == nil) then return false, "Setting the 'share' script-arg requires the 'sharepath' to be set as well." end stdnse.debug1("Using share chosen by the user: %s (%s)", share, path) else -- Try and find a share to use. status, share, path, shares = smb.share_find_writable(host) if(status == false) then return false, share .. " (May not have an administrator account)" end if(path == nil) then return false, string.format("Couldn't find path to writable share (we probably don't have admin access): '%s'", share) end stdnse.debug1("Found usable share %s (%s) (all writable shares: %s)", share, path, table.concat(shares, ", ")) end return true, share, path, shares end ---Recursively replace all variables in the 'setting' field with string variables -- found in the 'config' field and in the script-args passed by the user. -- --@param config The configuration table (used as a source of variables to replace). --@param setting The current setting field (generally a string or a table). --@return setting The setting with all values replaced. local function replace_variables(config, setting) if(type(setting) == "string") then -- Replace module fields with variables in the script-args argument for k, v in pairs(nmap.registry.args) do setting = string.gsub(setting, "$"..k, v) end -- Replace module fields with variables in the config file for k, v in pairs(config) do if((type(v) == "string" or type(v) == "boolean" or type(v) == "number") and k ~= "key") then setting = string.gsub(setting, "$"..k, v) end end elseif(type(setting) == "table") then for k, v in pairs(setting) do setting[k] = replace_variables(config, v) end end return setting end ---Takes the 'overrides' field from a module and replace any configuration variables. -- --@param config The config table. --@param overrides The overrides we're replacing values with. --@return config The new config table. local function do_overrides(config, overrides) if(overrides) then if(type(overrides) == 'string') then overrides = {overrides} end for i, v in pairs(overrides) do config[i] = v end end return config end ---Reads, prepares, parses, sanity checks, and pre-processes the configuration file (either the -- default, or the file passed as a parameter). -- --@param host The host table. --@param config A table to fill with configuration values. --@return status true or false --@return config The configuration table or an error message. local function get_config(host, config) local status local filename = nmap.registry.args.config config.enabled_modules = {} config.disabled_modules = {} -- Find the config file filename = locate_file(filename or 'default', 'lua') if(filename == nil) then return false, "Couldn't locate config file: file not found (make sure it has a .lua extension and is in nselib/data/psexec/)" end -- Load the config file local env = setmetatable({modules = {}; overrides = {}; module = function() stdnse.debug1("WARNING: Selected config file contains an unnecessary call to module()") end}, {__index = _G}) stdnse.debug1("Attempting to load config file: %s", filename) local file = loadfile(filename, "t", env) if(not(file)) then return false, "Couldn't load module file:\n" .. filename end -- Run the config file file() local modules = env.modules local overrides = env.overrides -- Generate a cipher key if(stdnse.get_script_args( "nocipher" )) then config.key = "" elseif(nmap.registry.args.key) then config.key = nmap.registry.args.key else local tmp = {} for i = 1, 127, 1 do tmp[i] = string.char(math.random(0x20, 0x7F)) end config.key = table.concat(tmp) config.key_index = 0 end -- Initialize the timeout config.timeout = 0 -- Figure out which share we're using (this is the first place in the script where a lot of traffic is generated -- -- any possible sanity checking should be done before this) status, config.share, config.path, config.all_shares = find_share(host) if(not(status)) then return false, config.share end -- Get information about the socket; it's a bit out of place here, but it should go before the mod loop status, config.lhost, config.lport, config.rhost, config.rport, config.lmac = smb.get_socket_info(host) if(status == false) then return false, "Couldn't get socket information: " .. config.lhost end -- Get the names of the files we're going to need status, config.service_name, config.service_file, config.temp_output_file, config.output_file = get_service_files(host) if(not(status)) then return false, config.service_name end -- Make sure the modules loaded properly -- NOTE: If you're here because of an error that 'modules' is undefined, it's likely because your configuration file doesn't have a -- proper modules table, or your configuration file has a module() declaration at the top. if(not(modules) or #modules == 0) then return false, string.format("Configuration file (%s) doesn't have a proper 'modules' table.", filename) end -- Make sure we got a proper modules array if(type(modules) ~= "table") then return false, string.format("The chosen configuration file, %s.lua, \z doesn't have a proper 'modules' table. If possible, it should be \z modified to have a public array called 'modules' that contains a \z list of all modules that will be run.", filename) end -- Loop through the modules for some pre-processing stdnse.debug1("Verifying uploadable executables exist") for i, mod in ipairs(modules) do local enabled = true -- Do some sanity checking if(mod.program == nil) then enabled = false if(mod.name) then mod.disabled_message = string.format("Configuration error: '%s': module doesn't have a program", mod.name) else mod.disabled_message = string.format("Configuration error: Module #%d doesn't have a program", i) end end -- Set some defaults, if the user didn't specify mod.name = mod.name or (string.format("%s %s", mod.program, mod.args or "")) mod.maxtime = mod.maxtime or 1 -- Check if they forgot the uploadibility if(mod.upload == nil) then enabled = false mod.disabled_message = string.format("Configuration error: '%s': 'upload' field is required", mod.name) end -- Check if the upload field is set wrong if(mod.upload ~= true and mod.upload ~= false) then enabled = false mod.disabled_message = string.format("Configuration error: '%s': 'upload' field has to be true or false", mod.name) end -- Check for incompatible fields with 'headless' if(mod.headless) then if(mod.find or mod.remove or mod.noblank or mod.replace or (mod.maxtime > 1) or mod.outfile) then enabled = false mod.disabled_message = string.format("Configuration error: '%s': 'headless' is incompatible with find, remove, noblank, replace, and maxtime", mod.name) end end -- Check for improperly formatted 'replace' if(mod.replace) then if(type(mod.replace) ~= "table") then enabled = false mod.disabled_message = string.format("Configuration error: '%s': 'replace' has to be a table of one-element tables (eg. replace = {{'a'='b'}, {'c'='d'}})", mod.name) end for _, v in ipairs(mod.replace) do if(type(v) ~= 'table') then enabled = false mod.disabled_message = string.format("Configuration error: '%s': 'replace' has to be a table of one-element tables (eg. replace = {{'a'='b'}, {'c'='d'}})", mod.name) end end end -- Set some default values if(mod.headless == nil) then mod.headless = false end if(mod.include_stderr == nil) then mod.include_stderr = true end -- Make sure required arguments are given if(mod.req_args) then if(type(mod.req_args) == 'string') then mod.req_args = {mod.req_args} end -- Keep a table of missing args so we can tell the user all the args they're missing at once local missing_args = {} for _, arg in ipairs(mod.req_args) do if(nmap.registry.args[arg] == nil) then table.insert(missing_args, arg) end end if(#missing_args > 0) then enabled = false mod.disabled_message = {} table.insert(mod.disabled_message, string.format("Configuration error: Required argument(s) ('%s') weren't given.", table.concat('", missing_args, "'))) table.insert(mod.disabled_message, "Please add --script-args=[arg]=[value] to your commandline to run this module") if(#missing_args == 1) then table.insert(mod.disabled_message, string.format("For example: --script-args=%s=123", missing_args[1])) else table.insert(mod.disabled_message, string.format("For example: --script-args=%s=123,%s=456...", missing_args[1], missing_args[2])) end end end -- Checks for the uploadable modules if(mod.upload) then -- Check if the module actually exists stdnse.debug1("Looking for uploadable module: %s or %s.exe", mod.program, mod.program) mod.filename = locate_file(mod.program, "exe") if(mod.filename == nil) then enabled = false stdnse.debug1("Couldn't find uploadable module %s, disabling", mod.program) mod.disabled_message = {string.format("Couldn't find uploadable module %s, disabling", mod.program)} if(mod.url) then stdnse.debug1("You can try getting it from: %s", mod.url) table.insert(mod.disabled_message, string.format("You can try getting it from: %s", mod.url)) table.insert(mod.disabled_message, "And placing it in Nmap's nselib/data/psexec/ directory") end else -- We found it stdnse.debug1("Found: %s", mod.filename) -- Generate a name to upload them as (we don't upload with the original names) status, mod.upload_name = smb.get_uniqueish_name(host, "txt", mod.filename) if(not(status)) then return false, "Couldn't generate name for uploaded file: " .. mod.upload_name end stdnse.debug1("Will upload %s as %s", mod.filename, mod.upload_name) end end -- Prepare extra files if(enabled and mod.extrafiles) then -- Make sure we have an array to help save on duplicate code if(type(mod.extrafiles) == "string") then mod.extrafiles = {mod.extrafiles} end -- Loop through all of the extra files mod.extrafiles_paths = {} for i, extrafile in ipairs(mod.extrafiles) do stdnse.debug1("Looking for extra module: %s", extrafile) mod.extrafiles_paths[i] = locate_file(extrafile) if(mod.extrafiles_paths[i] == nil) then return false, string.format("Couldn't find required file to upload: %s", extrafile) end stdnse.debug1("Found: %s", mod.extrafiles_paths[i]) end end -- Add the timeout to the total config.timeout = config.timeout + mod.maxtime -- Add the module to the appropriate list if(enabled) then table.insert(config.enabled_modules, mod) else table.insert(config.disabled_modules, mod) end end -- Make a list of *all* files (used for cleaning up) config.all_files = get_all_files(config) -- Finalize the timeout local max_timeout = nmap.registry.args.timeout or 15 config.timeout = math.max(config.timeout, max_timeout) stdnse.debug1("Timeout waiting for a response is %d seconds", config.timeout) -- Do config overrides if(overrides) then config = do_overrides(config, overrides) end -- Replace variable values in the configuration (this has to go last) stdnse.debug1("Replacing variables in the modules' fields") for i, mod in ipairs(config.enabled_modules) do for k, v in pairs(mod) do mod[k] = replace_variables(config, v) end end return true, config end ---Cipher (or uncipher) a string with a weak xor-based encryption. -- --@args str The string go cipher/uncipher. --@args config The config file for this host (stores the encryption key). --@return The decrypted string. local function cipher(str, config) local result = {} if(config.key == "") then return str end for i = 1, #str, 1 do local c = string.byte(str, i) c = string.char(c ~ string.byte(config.key, config.key_index + 1)) config.key_index = config.key_index + 1 config.key_index = config.key_index % #config.key result[i] = c end return table.concat(result) end local function get_overrides() -- Create some overrides: -- 0x00004000 = Encrypted -- 0x00002000 = Don't index this file -- 0x00000100 = Temporary file -- 0x00000800 = Compressed file -- 0x00000002 = Hidden file -- 0x00000004 = System file local attr = 0x00000004 | 0x00000002 | 0x00000800 | 0x00000100 | 0x00002000 | 0x00004000 -- Let the user override this behaviour if(stdnse.get_script_args( "nohide" )) then attr = 0 end -- Create the overrides return {file_create_attributes=attr} end --- Check if an nmap_service.exe file is the XOR-encoded version from the 5.21 -- release. It works by checking the first few bytes against a known pattern. -- Returns true or false, or else nil and -- an error message. -- @param filename the name of the file to check. -- @return status -- @return error message local function service_file_is_xor_encoded(filename) local f, bytes, msg f, msg = io.open(filename) if not f then return nil, msg end bytes = f:read(2) f:close() if not bytes or #bytes < 2 then return nil, "Can't read from service file" end -- This is the XOR-inverse of "MZ". return bytes == "\xb2\xa5" end ---Upload all of the uploadable files to the remote system. -- --@param host The host table. --@param config The configuration table. --@return status true or false --@return err An error message if status is false. local function upload_everything(host, config) local is_xor_encoded, msg local overrides = get_overrides() -- In Nmap 5.20, it was discovered that nmap_service.exe file was -- causing false positives in antivirus software. In an effort to avoid -- this, in version 5.21 the file was obfuscated by XORing all its bytes -- with 0xFF. That didn't work, so now the file is not included in the -- distribution. But it means we must check if we are dealing with the -- original or XOR-encoded version of the file. is_xor_encoded, msg = service_file_is_xor_encoded(config.local_service_file) if is_xor_encoded == nil then return nil, msg elseif is_xor_encoded then stdnse.debug2("%s is the XOR-encoded version from the 5.21 release.", config.local_service_file) end -- Upload the service file stdnse.debug1("Uploading: %s => \\\\%s\\%s", config.local_service_file, config.share, config.service_file) local status, err status, err = smb.file_upload(host, config.local_service_file, config.share, "\\" .. config.service_file, overrides, is_xor_encoded) if(status == false) then cleanup(host, config) return false, string.format("Couldn't upload the service file: %s\n", err) end stdnse.debug1("Service file successfully uploaded!") -- Upload the modules and all their extras stdnse.debug1("Attempting to upload the modules") for _, mod in ipairs(config.enabled_modules) do -- If it's an uploadable module, upload it if(mod.upload) then stdnse.debug1("Uploading: %s => \\\\%s\\%s", mod.filename, config.share, mod.upload_name) status, err = smb.file_upload(host, mod.filename, config.share, "\\" .. mod.upload_name, overrides) if(status == false) then cleanup(host, config) return false, string.format("Couldn't upload module %s: %s\n", mod.program, err) end end -- If it requires extra files, upload them, too if(mod.extrafiles) then -- Convert to a table, if it's a string if(type(mod.extrafiles) == "string") then mod.extrafiles = {mod.extrafiles} end -- Loop over the files and upload them for i, extrafile in ipairs(mod.extrafiles) do local extrafile_local = mod.extrafiles_paths[i] stdnse.debug1("Uploading extra file: %s => \\\\%s\\%s", extrafile_local, config.share, extrafile) status, err = smb.file_upload(host, extrafile_local, config.share, extrafile, overrides) if(status == false) then cleanup(host, config) return false, string.format("Couldn't upload extra file %s: %s\n", extrafile_local, err) end end end end stdnse.debug1("Modules successfully uploaded!") return true end ---Create the service on the remote system. --@param host The host object. --@param config The configuration table. --@return status true or false --@return err An error message if status is false. local function create_service(host, config) local status, err = msrpc.service_create(host, config.service_name, config.path .. "\\" .. config.service_file) if(status == false) then stdnse.debug1("Couldn't create the service: %s", err) cleanup(host, config) if(string.find(err, "MARKED_FOR_DELETE")) then return false, "Service is stuck in 'being deleted' phase on remote machine; try setting script-args=randomseed=abc for now" else return false, string.format("Couldn't create the service on the remote machine: %s", err) end end return true end ---Create the list of parameters we're using to start the service. This consists -- of a few global params, then a group of parameters with options for each process -- that's going to be started. -- --@param config The configuration table. --@return status true or false --@return params A table of parameters if status is true, or an error message if status is false. local function get_params(config) local count = 0 -- Build the table of parameters to pass to the service local params = {} table.insert(params, config.path .. "\\" .. config.output_file) table.insert(params, config.path .. "\\" .. config.temp_output_file) table.insert(params, tostring(#config.enabled_modules)) table.insert(params, "0") table.insert(params, config.key) table.insert(params, config.path) for _, mod in ipairs(config.enabled_modules) do if(mod.upload) then table.insert(params, config.path .. "\\" .. mod.upload_name .. " " .. (mod.args or "")) else table.insert(params, mod.program .. " " .. (mod.args or "")) end table.insert(params, (mod.env or "")) table.insert(params, tostring(mod.headless)) table.insert(params, tostring(mod.include_stderr)) table.insert(params, mod.outfile or "") end return true, params end ---Start the service on the remote machine. -- --@param host The host object. --@param config The configuration table. --@param params The parameters to pass to the service, likely from the get_params function. --@return status true or false --@return err An error message if status is false. local function start_service(host, config, params) local status, err = msrpc.service_start(host, config.service_name, params) if(status == false) then stdnse.debug1("Couldn't start the service: %s", err) return false, string.format("Couldn't start the service on the remote machine: %s", err) end return true end ---Poll for the output file on the remote machine until either the file is created, or the timeout -- expires. -- --@param host The host object. --@param config The configuration table. --@return status true or false --@return result The file if status is true, or an error message if status is false. local function get_output_file(host, config) stdnse.debug1("Waiting for output file to be created (timeout = %d seconds)", config.timeout) local status, result local i = config.timeout while true do status, result = smb.file_read(host, config.share, "\\" .. config.output_file, nil, {file_create_disposition=1}) if(not(status) and result ~= "NT_STATUS_OBJECT_NAME_NOT_FOUND") then -- An unexpected error occurred stdnse.debug1("Couldn't read the file: %s", result) cleanup(host, config) return false, string.format("Couldn't read the file from the remote machine: %s", result) end if(not(status) and result == "NT_STATUS_OBJECT_NAME_NOT_FOUND") then -- An expected error occurred; if this happens, we just wait if(i == 0) then stdnse.debug1("Error in remote service: output file was never created!") cleanup(host, config) return false, "Error in remote service: output file was never created" end stdnse.debug1("Output file %s doesn't exist yet, waiting for %d more seconds", config.output_file, i) stdnse.sleep(1) i = i - 1 end if(status) then break end end return true, result end ---Decide whether or not a line should be included in the output file, based on the module's -- find, remove, and noblank settings. local function should_be_included(mod, line) local removed, found -- Remove lines from the output, if the module requested it removed = false if(mod.remove and #mod.remove > 0) then -- Make a single string into a table to save code if(type(mod.remove) ~= 'table') then mod.remove = {mod.remove} end -- Loop through the module's find table to see if any of the lines match for _, remove in ipairs(mod.remove) do if(string.match(line, remove)) then removed = true break end end end -- Remove blank lines if we're supposed to if(mod.noblank and line == "") then removed = true end -- If the line wasn't removed, and we are searching for specific text, do the search found = false if(mod.find and #mod.find > 0 and not(removed)) then -- Make a single string a table to save duplicate code if(type(mod.find) ~= 'table') then mod.find = {mod.find} end -- Loop through the module's find table to see if any of the lines match for _, find in ipairs(mod.find) do if(string.match(line, find)) then found = true break end end else found = true end -- Only display the line if it's found and not removed return (found and not(removed)) end ---Alter a line based on the module's 'replace' setting. local function do_replacements(mod, line) if(mod.replace) then for _, v in pairs(mod.replace) do line = string.gsub(line, v[1], v[2]) end end return line end ---Parse the output file into a neat array. local function parse_output(config, data) -- Allow 'data' to be nil. This lets us skip most of the effort when all mods are disabled data = data or "" -- Split the result at newlines local lines = stringaux.strsplit("\n", data) local module_num = -1 local mod = nil local result = nil -- Loop through the lines and parse them into the results table local results = {} for _, line in ipairs(lines) do if(line ~= "") then local this_module_num = tonumber(string.sub(line, 1, 1)) -- Get the important part of the line line = string.sub(line, 2) -- Remove the Windows endline (0x0a) from the string (these are left in up to this point to maintain -- the ability to download binary files, if that ever comes up line = string.gsub(line, "\r", "") -- If the module_number has changed, increment to the next module if(this_module_num ~= (module_num % 10)) then -- Increment our module number if(module_num < 0) then module_num = 0 else module_num = module_num + 1 end -- Go to the next module, and make sure it exists mod = config.enabled_modules[module_num + 1] if(mod == nil) then stdnse.debug1("Server's response wasn't formatted properly (mod %d); if you can reproduce, place report to dev@nmap.org", module_num) stdnse.debug1("--\n" .. string.gsub("%%", "%%", data) .. "\n--") return false, "Server's response wasn't formatted properly; if you can reproduce, place report to dev@nmap.org" end -- Save this result if(result ~= nil) then table.insert(results, result) end result = {} result['name'] = "" result['lines'] = {} if(mod.name) then result['name'] = mod.name else result['name'] = string.format("'%s %s;", mod.program, (mod.args or "")) end end local include = should_be_included(mod, line) -- If we're including it, do the replacements if(include) then line = do_replacements(mod, line) table.insert(result, line) end end end table.insert(results, result) -- Loop through the disabled modules and print them out for _, mod in ipairs(config.disabled_modules) do local result = {} result['name'] = mod.name if(mod.disabled_message == nil) then mod.disabled_message = {"No reason for disabling the module was found"} end if(type(mod.disabled_message) == 'string') then mod.disabled_message = {mod.disabled_message} end for _, message in ipairs(mod.disabled_message) do table.insert(result, "WARNING: " .. message) end table.insert(results, result) end return true, results end action = function(host) local status, result, err local key local i local params local config = {} local files -- First check for nmap_service.exe; we can't do anything without it. stdnse.debug1("Looking for the service file: nmap_service or nmap_service.exe") config.local_service_file = locate_file("nmap_service", "exe") if (config.local_service_file == nil) then if nmap.verbosity() > 0 then return string.format([[ Can't find the service file: nmap_service.exe (or nmap_service). Due to false positives in antivirus software, this module is no longer included by default. Please download it from %s and place it in nselib/data/psexec/ under the Nmap DATADIR. ]], NMAP_SERVICE_EXE_DOWNLOAD) else return end end -- Parse the configuration file status, config = get_config(host, config) if(not(status)) then return stdnse.format_output(false, config) end if(#config.enabled_modules > 0) then -- Start by cleaning up, just in case. cleanup(host, config) -- If the user just wanted a cleanup, do it if(stdnse.get_script_args( "cleanup" )) then return stdnse.format_output(true, "Cleanup complete.") end -- Check if any of the files exist status, result, files = smb.files_exist(host, config.share, config.all_files, {}) if(not(status)) then return stdnse.format_output(false, "Couldn't log in to check for remote files: " .. result) end if(result > 0) then local response = {} table.insert(response, "One or more output files already exist on the host, and couldn't be removed. Try:") table.insert(response, "* Running the script with --script-args=cleanup=1 to force a cleanup (passing -d and looking for error messages might help),") table.insert(response, "* Running the script with --script-args=randomseed=ABCD (or something) to change the name of the uploaded files,") table.insert(response, "* Changing the share and path using, for example, --script-args=share=C$,sharepath=C:, or") table.insert(response, "* Deleting the affected file(s) off the server manually (\\\\" .. config.share .. "\\" .. table.concat(files, ", \\\\" .. config.share .. "\\") .. ")") return stdnse.format_output(false, response) end -- Upload the modules status, err = upload_everything(host, config) if(not(status)) then cleanup(host, config) return stdnse.format_output(false, err) end -- Create the service status, err = create_service(host, config) if(not(status)) then cleanup(host, config) return stdnse.format_output(false, err) end -- Get the table of parameters to pass to the service when we start it status, params = get_params(config) if(not(status)) then cleanup(host, config) return stdnse.format_output(false, params) end -- Start the service status, params = start_service(host, config, params) if(not(status)) then cleanup(host, config) return stdnse.format_output(false, params) end -- Get the result status, result = get_output_file(host, config, config.share) if(not(status)) then cleanup(host, config) return stdnse.format_output(false, result) end -- Do a final cleanup cleanup(host, config) -- Uncipher the file result = cipher(result, config) end -- Build the output into a nice table local response status, response = parse_output(config, result) if(status == false) then return stdnse.format_output(false, "Couldn't parse output: " .. response) end -- Add a warning if nothing was enabled if(#config.enabled_modules == 0) then if(#response == 0) then response = {"No modules were enabled! Please check your configuration file."} else table.insert(response, "No modules were enabled! Please fix any errors displayed above, or check your configuration file.") end end -- Return the string return stdnse.format_output(true, response) end