ASN / RPKI validity / BGP stats / IPv4v6 / Prefix / ASPath / Organization / IP reputation / IP geolocation / IP fingerprinting / Network recon / lookup tool / Web traceroute server.
This script serves the purpose of having a quick OSINT command line tool at disposal when investigating network data, which can come in handy in incident response scenarios as well (with features such as bulk geolocation and threat scoring).
It can be used as a recon tool by querying Shodan for data about any type of target (CIDR blocks/URLs/single IPs/hostnames). This will quickly give the user a complete breakdown about open ports, known vulnerabilities, known software and hardware running on the target, and more - without ever sending a single packet to the target. JSON output of the results, multiple simultaneous targets and IP list file inputs and are also supported. Click here for more information about Shodan scanning mode.
It can also be used as a web-based traceroute server, by running it in listening mode and launching lookups and traces from a local or remote browser (via a bookmarklet or custom search engine) or terminal (via curl
, elinks
or similar tools). Click here for more information about server mode functionality.
Furthermore, it can serve as a self-hosted lookup API endpoint and output JSON-formatted data while running in both interactive and server mode. Click here for more information about API mode functionality.
It will lookup relevant Autonomous System information for any given AS number, including:
INET(6)NUM
object (actual LIR allocation).It will perform an AS path trace (using mtr and retrieving AS data from the results) for single IPs or DNS results, optionally reporting detailed data for each hop, such as RPKI ROA validity, organization/network name, geographic location, etc.
It will detect IXPs (Internet Exchange Points) traversed during the trace, and highlight them for clarity.
It will attempt to lookup all relevant abuse contacts for any given IP or prefix.
It will perform RPKI validity lookups for every possible IP. Data is validated using the RIPEStat RPKI validation API. For path traces, the tool will match each hop's ASN/Prefix pair (retrieved from the Prefix Whois public server) with relevant published RPKI ROAs. In case of origin AS mismatch or unallowed more-specific prefixes, it will warn the user of a potential route leak / BGP hijack along with the offending AS in the path (requires -d
option, see below for usage info).
It will perform IP geolocation lookups according to the logic described below.
It will perform IP reputation, noise classification and in-depth threat analysis reporting (especially useful when investigating foreign IPs from log files).
It will perform IP fingerprinting using Shodan's InternetDB API and report any known vulnerabilities, open ports and services/operating system/hardware pertaining to target IPs and individual trace hops (detailed traces only).
It will perform IP type identification (Anycast IP/Mobile network/Proxy host/Datacenter or hosting provider/IXP prefix) for target IPs and individual trace hops. Broad type classification comes from ip-api, while detailed DC+region identification comes from incolumitas.com
It is possible to search by organization name in order to retrieve a list of IPv4/6 network ranges related to a given company. A multiple choice menu will be presented if more than one organization matches the search query.
It is possible to search for ASNs matching a given name, in order to map the ASNs for a given organization. The list will be enriched by each result's AS rank and useful tags highlighting the highest-ranking ASNs found.
It is possible to quickly identify the transit/upstream AS network(s) for a given prefix, through analysis of observed BGP updates and ASPATHs.
Lookup data can be integrated by third party tools by choosing JSON output and parsing the results externally, turning the script into a lookup API endpoint.
Screenshots for every lookup option are below.
The script uses the following services for data retrieval:
It also provides hyperlinks (in server mode) to the following external services when appropriate:
Requires Bash v4.2+. Tested on:
Linux
FreeBSD
Windows (WSL2, Cygwin)
MacOS (thanks Antonio Prado and Alessandro Barisone)
IPv4 lookup with IP type detection (Anycast, Hosting/DC) and classification as good
IPv4 lookup (bad reputation IP) with threat analysis/scoring, CPE/CVE identification and open ports reporting
IP fingerprinting with advanced datacenter+region identification, known vulnerabilities affecting the target and honeypot identification according to Shodan data
IPv6 lookup
Autonomous system number lookup with AS ranking, operational region, BGP stats and incident history, peering and prefix informations
Hostname/URL lookup
ASPath trace to www.github.com
ASPath trace traversing both an unannounced PNI prefix (FASTWEB->SWISSCOM at hop 11) and an IXP (SWISSCOM -> RCN through Equinix Ashburn at hop 16)
Detailed ASPath trace to 8.8.8.8 traversing the Milan Internet Exchange (MIX) IXP peering LAN at hop 6
Organization search for "github"
Scanning for Shodan informations for a list of IPs
Displaying a list of CIDR blocks allocated to Jamaica
Performing bulk extraction, geolocation and stats for IPs from a logfile
Suggested ASNs (and respective AS rankings) for "google"
A large tier-1 network (COMCAST, AS7922) prefix is reachable through multiple other tier-1 networks like COGENT (AS174), LEVEL3 (AS3356) etc. - likely through settlement-free peering rather than BGP transit:
Transit identification for a multihomed AS (AS30036 announces this prefix to Hurricane and GTT in a balanced way):
Preferred transit identification - Chinese UNICOM AS is a large network, but likely prefers Russian TRANSTELECOM (AS20485) transit over TELIA (AS1299), HURRICANE (AS6939), GTT (AS3257) and others:
To run the script without installing it locally, you have the following options:
Docker (thanks Gianni Stubbe, anarcat, Francesco Colista, arbal)
_Note: the Docker image runs by default in server mode, if no parameters are given. This is equivalent to running the tool as asn -l 0.0.0.0
(run server, bind to all IPv4 interfaces - this is necessary to expose the server port to the host machine). You can run the server with different options by explicitly passing -l [options]
. It's also possible to pass an IpQualityScore, ipinfo.io and/or Cloudflare API token (both client and server runs) by setting, respectively, the IQS_TOKEN
, IPINFO_TOKEN
and CLOUDFLARE_TOKEN
environment variables (examples below) in the container._
Usage examples:
docker run -it -p 49200:49200 nitefood/asn
docker run -it nitefood/asn 1.1.1.1
docker run -it -e IQS_TOKEN="xxx" nitefood/asn [...]
docker run -it -e IQS_TOKEN="xxx" -e IPINFO_TOKEN="yyy" -e CLOUDFLARE_TOKEN="zzz" nitefood/asn [...]
Google Cloud Shell
Note: server mode is supported out of the box in Cloud Shell, just follow the bookmarklet link that will be shown at server launch to access the VM for remote lookups.
1. Clone the repository in Cloud Shell by clicking the following button:
2. Prepare the GCP environment by launching ./cloudshell_bootstrap.sh
3. (OPTIONAL) Input your API tokens when requested to enable full script features
This script requires BASH v4.2 or later. You can check your version by running from your shell:
bash -c 'echo $BASH_VERSION'
After installation, you can use the script by running the asn
command.
Note: this method is recommended as it will always get you the latest version of the script.
Some packages are required for full functionality: * **Debian 10 / Ubuntu 20.04 (or newer):** ``` apt -y install curl whois bind9-host mtr-tiny jq ipcalc grepcidr nmap ncat aha ``` * **Debian 9 / Ubuntu 18.04 (or older):** ``` apt -y install curl whois bind9-host mtr-tiny jq ipcalc grepcidr nmap git gcc make && \ git clone https://github.com/theZiz/aha.git && \ make install -C aha/ ``` * **CentOS / RHEL / Rocky Linux 9:** ``` dnf -y install epel-release && \ dnf -y install curl whois bind-utils mtr jq nmap nmap-ncat ipcalc aha grepcidr ``` * **CentOS / RHEL / Rocky Linux 8:** *(thanks [Robert Scheck](https://github.com/robert-scheck))* ``` dnf -y install epel-release 'dnf-command(copr)' && \ dnf -y copr enable robert/ipcalc && \ dnf -y install curl whois bind-utils mtr jq nmap nmap-ncat ipcalc aha grepcidr ``` * **CentOS / RHEL 7:** *(thanks [Robert Scheck](https://github.com/robert-scheck))* ``` yum -y install epel-release yum-plugin-copr && \ yum -y copr enable robert/ipcalc && \ yum -y install curl whois bind-utils mtr jq nmap nmap-ncat ipcalc aha grepcidr && \ hash -d ipcalc ``` * **Fedora:** ``` dnf -y install curl whois bind-utils mtr jq nmap nmap-ncat ipcalc aha grepcidr ``` * **openSUSE Leap 15.5 (or newer), openSUSE Tumbleweed** ``` zypper in -y curl whois bind-utils mtr jq nmap ncat ipcalc aha grepcidr ``` * **FreeBSD**: ``` env ASSUME_ALWAYS_YES=YES pkg install bash coreutils curl whois mtr jq ipcalc grepcidr nmap aha ``` * **Windows**: * **using [WSL2](https://docs.microsoft.com/en-us/windows/wsl/about) (recommended):** Install Windows Subsystem for Linux (v2) by following Microsoft's [guide](https://docs.microsoft.com/en-us/windows/wsl/install-win10#manual-installation-steps). On step 6, choose one of the Linux distributions listed above (Ubuntu 20.04 LTS is recommended). Once your WSL2 system is up and running, open a Linux terminal and follow the prerequisite installation instructions above for your distribution of choice. > *Note for WSL2 users: Check [this](https://devblogs.microsoft.com/commandline/systemd-support-is-now-available-in-wsl/) page for details on how to activate **systemd** if you plan to install the [asn service](#optional-installing-the-asn-server-as-a-system-service).* * **using [Cygwin](https://cygwin.com/index.html):** Most of the prerequisite packages listed above for *Debian 10 / Ubuntu 20.04 (or newer)* are obtainable directly with Cygwin's own Setup wizard (or through scripts like *apt-cyg*). You will still have to manually compile (or find a suitable third-party precompiled binary) the *mtr*, *grepcidr* and *aha* tools. Instructions on how to do so can be found directly on the respective projects homepages.
Afterwards, to install the **asn** script from your shell to **/usr/bin**: `curl "https://raw.githubusercontent.com/nitefood/asn/master/asn" > /usr/bin/asn && chmod 0755 /usr/bin/asn`
Note: packages may not reflect the latest version, check Repology first.
Packaged versions of the tool are available for the following distributions:
* **Debian-based:** *(thanks [Marcos Rodrigues de Carvalho](https://github.com/odaydebian))* > *Debian 13 / Sid*\ > *Ubuntu 24.04 (or newer)*\ > *Kali (rolling)*\ > *Raspbian (testing)* ``` sudo apt update && sudo apt install asn ``` * **Manjaro / Arch Linux:** *(thanks [Worty](https://github.com/worty))* ``` yay -S asn-git ``` * **Alpine Linux 3.18 (or newer)** *(thanks [Francesco Colista](https://github.com/fcolista))* ``` apk add -X https://dl-cdn.alpinelinux.org/alpine/v3.19/community asn ``` * **NixOS** *(thanks [devhell](https://github.com/devhell))* * Package [here](https://github.com/NixOS/nixpkgs/tree/master/pkgs/applications/networking/asn) * **MacOS** *(using [Homebrew](https://formulae.brew.sh/formula/asn), thanks [filippovitale](https://github.com/filippovitale))* ``` brew install asn ``` >*Note for MacOS users:* > > *Homebrew has a [policy](https://github.com/Homebrew/homebrew-core/issues/35085#issuecomment-447184214) not to install any binary with the **setuid** bit, and mtr (or actually, the mtr-packet helper binary that comes with it) requires to elevate to root to perform traces (good explanations for this can be found [here](https://github.com/traviscross/mtr/issues/204#issuecomment-723961118) and [here](https://github.com/traviscross/mtr/blob/master/SECURITY)). If mtr (and therefore `asn`) traces are not working on your system, you should either run `asn` as root using **sudo**, or set the proper SUID permission bit on the mtr (or better, on the mtr-packet) binary.*
Note: this step is optional, and these instructions are only for systemd-based Linux systems (most current major distributions).
To control the asn server with utilities like systemctl and service, and to enable it to automatically start at boot, follow these steps:
/etc/systemd/system/asn.service
with the following content (make sure you edit the ExecStart line to match your installation path and desired startup options):[Unit]
Description=ASN lookup and traceroute server
After=network.target
StartLimitIntervalSec=0
[Service]
Type=simple
Restart=always
RestartSec=1
User=nobody
ExecStart=/usr/bin/asn -l 0.0.0.0
[Install]
WantedBy=multi-user.target
setcap cap_net_raw+ep $(which mtr-packet)
Explanation: this will allow mtr-packet to create raw sockets (and thus perform traces) when launched as an unprivileged user (we're setting up the service to run as user nobody for added security), without the requirement of the setuid-root bit and without having to invoke mtr as root. A thorough explanation for this can be found here.systemctl start asn
systemctl stop asn
systemctl status asn
journalctl -f -u asn
systemctl enable asn
systemctl disable asn
The script can be configured to make use of your API tokens to enhance its functionalities.
The currently supported API tokens are:
The geolocation provider of choice for single lookups (i.e. when not running bulk geolocation queries with the `-g` option) is **ipinfo.io**.
By default, the script uses the free (no API key) tier that supports up to **1,000** geolocation requests per day. In order to boost this limit (for free) to **50,000** requests per month, an API key token is required.
In order to obtain an API token, after [signing up](https://ipinfo.io/signup), the API token can be found in the [token section](https://ipinfo.io/account/token) of your reserved area. Once copied, the token should be written to one of the following files (parsed in that order):
`$HOME/.asn/ipinfo_token` or
`/etc/asn/ipinfo_token`
The `/etc`-based file should be used when running asn in **server mode**. The `$HOME`-based file takes precedence if both files exist, and is ideal for **user mode** (that is, running `asn` interactively from the command line).
In order to do so, you can use the following command:
***User mode:***
`TOKEN="
The script will perform first-level IPv4/v6 reputation lookups using [StopForumSpam](https://www.stopforumspam.com/), and in case of a match it will perform a second-level, in-depth threat analysis for targets and trace hops using the [IPQualityScore](https://www.ipqualityscore.com/) API. The StopForumSpam API is free and requires no sign-up, and the service aggregates a [huge](https://www.stopforumspam.com/contributors) amount of blacklist feeds.
Still, in order to use the IPQualityScore API for in-depth threat reporting, it's necessary to [sign up](https://www.ipqualityscore.com/create-account) for their service (it's free) and get an API token (it will be emailed to you on sign-up), which will entitle you to 5000 free lookups per month.
Once obtained, the api token should be written to one of the following files (parsed in that order):
`$HOME/.asn/iqs_token` or
`/etc/asn/iqs_token`
The `/etc`-based file should be used when running asn in **server mode**. The `$HOME`-based file takes precedence if both files exist, and is ideal for **user mode** (that is, running `asn` interactively from the command line).
In order to do so, you can use the following command:
***User mode:***
`TOKEN="
When this token is available, an additional lookup will be enabled for **autonomous system** targets, in order to enumerate the BGP incidents (both **BGP hijacks** and **BGP route leaks**) involving the target ASN.
The script will use the [Cloudfare Radar](https://radar.cloudflare.com/) API to retrieve the amount of incidents involving the target ASN in the past 12 months. Additionally, it will report how many incidents saw the target ASN as a **hijacker** or as a **victim**.
The Cloudflare Radar API is **free** to use, but requires a registration. The steps are:
1. [Sign up](https://dash.cloudflare.com/sign-up) for a free Cloudflare account and **validate your email**
2. From the [Cloudflare dashboard](https://dash.cloudflare.com/profile/api-tokens/), go to **My Profile > API Tokens**.
3. Select **Create Token**
4. Choose the "*Read Cloudflare Radar data*" template
5. Click **Continue to summary** (the default values are fine)
6. Click **Create token**
Once obtained, the api token should be written to one of the following files (parsed in that order):
`$HOME/.asn/cloudflare_token` or
`/etc/asn/cloudflare_token`
The `/etc`-based file should be used when running asn in **server mode**. The `$HOME`-based file takes precedence if both files exist, and is ideal for **user mode** (that is, running `asn` interactively from the command line).
In order to do so, you can use the following command:
***User mode:***
`TOKEN="
asn [OPTIONS] [TARGET]
asn [-v] -l [SERVER OPTIONS]
where TARGET
can be one of the following:
Options:
-t
.asnrc option equivalent:
MTR_TRACING=true
(default:true
)
-d
.asnrc option equivalent:
DETAILED_TRACE=true
(default:false
)
-n
.asnrc option equivalent:
MTR_TRACING=false
(default:true
),ADDITIONAL_INETNUM_LOOKUP=false
(default:true
)
-s
-o
-a
-u
-c
-g
-l
-j
jq
or other parsers), or storing the lookup results..asnrc option equivalent:
JSON_OUTPUT=true
(default:false
)
-J
.asnrc option equivalent:
JSON_PRETTY=true
(default:false
)
-m
.asnrc option equivalent:
MONOCHROME_MODE=true
(default:false
)
-v
asn
will log all output (external calls and their response data) to the location defined by $ASN_LOGFILE
(by default the logfile can be found at $HOME/asndebug.log
)..asnrc option equivalent:
ASN_DEBUG=true
(default:false
)
-h
Server Options:
BIND_ADDRESS
asn -l 0.0.0.0
).asnrc option equivalent:
DEFAULT_SERVER_BINDADDR_v4="<IPv4address>"
(default:"127.0.0.1"
) andDEFAULT_SERVER_BINDADDR_v6="<IPv6address>"
(default:"::1"
)
BIND_PORT
asn -l 12345
).asnrc option equivalent:
DEFAULT_SERVER_BINDPORT="<port>"
(default:"49200"
)
BIND_ADDRESS BIND_PORT
asn -l ::1 12345
)-v
.asnrc option equivalent:
ASN_DEBUG=true
(default:false
)
--allow host[,host,...]
--allowfile file
--deny host[,host,...]
--denyfile file
--max-conns <n>
Note: Every option in server mode (after
-l
) is passed directly to the ncat listener. Refer toman ncat
for more details on the available commands. Unless specified, the default IP:PORT values of 127.0.0.1:49200 (for IPv4) or [::1]:49200 (for IPv6) will be used (e.g.asn -l
)
TARGET
type, if invoked with -t
, -n
, -d
or without options,$HOME/.asnrc
)Options defaults can be overridden by creating a file called .asnrc
in the user's home directory.
The following values are the defaults. Any (or all) of them can be specified in the settings file and adjusted to the user's preference:
ASN_LOGFILE="$HOME/asndebug.log"
MTR_TRACING=true
ADDITIONAL_INETNUM_LOOKUP=true
DETAILED_TRACE=false
MTR_ROUNDS=5
MAX_CONCURRENT_SHODAN_REQUESTS=10
SHODAN_SHOW_TOP_N=5
MONOCHROME_MODE=false
ASN_DEBUG=false
JSON_OUTPUT=false
JSON_PRETTY=false
DEFAULT_SERVER_BINDADDR_v4="127.0.0.1"
DEFAULT_SERVER_BINDADDR_v6="::1"
DEFAULT_SERVER_BINDPORT="49200"
IQS_ALWAYS_QUERY=false
IQS_CUSTOM_SETTINGS=""
-d
| DETAILED_TRACE=true
)[-d|--detailed]
command line switch. This will enable querying the public pWhois server and the RIPEStat RPKI validation API for every hop in the mtr trace. Relevant info will be displayed as a "tree" below the hop data, in addition to Team Cymru's server output (which only reports the AS name that the organization originating the prefix gave to its autonomous system number). This can be useful to figure out more details regarding the organization's name, the prefix' intended designation, and even (to a certain extent) its geographical scope.
Furthermore, this will enable a warning whenever RPKI validation fails for one of the hops in the trace, indicating which AS in the path is wrongly announcing (as per current pWhois data) the hop prefix, indicating a potential route leak or BGP hijacking incident.-o
).
in their name), pass the [-o|--organization]
command line switch.-a
)-u
)-l
)Reputation is also enriched with IP noise classification (addresses that have been observed scanning the Internet, and very likely to appear in your logs), taken from GreyNoise. This will also help identify known-good IPs (e.g. Google networks, CDNs, etc.) from aggressive, known-malicious scanners.
The script will perform IP and trace hop geolocation with this logic:
The script will use the ip-api, incolumitas.com, ipinfo.io and PeeringDB services to classify target IPs and trace hops into these categories:
whois
lookup when Team Cymru, pWhois and PeeringDB have no info about the IP address or prefix. This is usually the case with some PNI prefixes, and will give better insight into the path taken by packets.Server mode requires two tools for its functionality: ncat
and aha
. Specifically, aha (the ANSI->HTML converter) v0.5+ is required. The ncat tool is contained inside the nmap package on older distributions (e.g. Ubuntu 18.04, Debian 9), while it is packaged as a standalone tool on newer ones.
Please refer to the installation section and run the appropriate commands to install the required packages for your operating system, and optionally to install the asn server as a systemd service.
The main advantage of running lookups from the browser, is that every IP address and AS number gets converted into a hyperlink, allowing to perform subsequent lookups by simply clicking on them.
When looking up an URL/hostname/domain, quick WHOIS info and links to relevant external resources will be available in the results.
When looking up an AS number, all peering ASNs will be clickable. Also, if an AS peers at a public facility, PeeringDB info for that facility will be linked directly. Furthermore, additional external BGP information sources will be linked, directly for the target ASN.
Here are some examples:
Once started in server mode, asn
will spin up a custom webserver waiting for browser requests. This is what the server-side console looks like:
The server is now ready to accept browser requests (only from the local machine, in this case - since I've launched it with no command line switches, which defaults to listening on 127.0.0.1:49200. Refer to the usage section for more information about the available server options).
Visit this page in your browser and follow the instructions to copy the bookmarklet to your bookmarks toolbar:
The bookmarklet is actually a small piece of Javascript code which will grab the hostname of the website you're currently visiting in the browser, and pass it to the server through a simple HTTP GET request. The server then proceeds to perform the lookup and traceroute (from its own viewpoint, just like it does when ran interactively from the command line), and feed the results to your browser through an HTML page, mimicking the effect of a scrolling terminal.
Note: The link you drag to the bookmarks bar is actually a minified (i.e.: compacted) version of the source javascript code, but for reference, here's the full source:
javascript:(function () { var asnserver = "localhost:49200"; var target = window.location.hostname; var width = screen.width - screen.width / 7; var height= screen.height - screen.height / 4; var left = window.innerWidth / 2 - width / 2; var top = window.innerHeight / 2 - height / 2; window.open("http://" + asnserver + "/asn_lookup&" + target, "newWindow", "width=" + width + ",height=" + height + ",top=" + top + ",left=" + left); })();
If you want to "un-minify" the actual bookmarklet code, you can refer to this site
Once the trace is finished, an option to share the output on termbin is given to the user. This makes for quick sharing of the traceroute or lookup output with other people:
In order to take full advantage of having asn
inside the browser, it is possible to configure it as a custom search engine for the browser search bar. This allows to leverage the server to search for ASNs, URLs, IPs, Hostnames, and so on, depending on the search string.
Generally speaking, this implies instructing the browser that when a certain keyword is prepended to a search, the following characters (the actual search string, identified by %s
) have to be passed to a certain URL. The URL is then composed according to this logic, and opened just like a normal webpage.
I've used @asn
for my keyword, but anything would do. In order to speed up things, one could very well use a shorter tag (e.g. #
) that, when used in the address bar, automatically switches your search engine to the ASN Lookup server.
Note that the leading @
sign is not mandatory, just handy since it doesn't get in the way of normal searches, but there's much freedom with that.
For quick reference, the location URL string to enter (for both Firefox and Chrome) is: http://127.0.0.1:49200/asn_lookup&%s
. Of course that sends lookup requests to the locally running ASN server.
Here's how to add a search engine in Firefox and Chrome:
Firefox:
Simply create a new bookmark and fill its details like this:
Afterwards, you will be able to run queries and traceroutes by simply entering, for example, @asn 8.8.8.8
in the browser's location bar.
Chrome:
Right click the location bar and select Manage search engines...
Click Add:
Fill in the details as shown below:
As usual, the keyword is entierly customizable to your preference.
Other browsers:
In order to access the server remotely, beside binding to 0.0.0.0
(or any other relevant IP address for your scenario), if the host is behind a NAT router, you'll need to forward the listening port (BIND_PORT
) from the host/router outside IP to the actual machine where the ASN server is running on.
It is a single TCP port (by default TCP/49200
), and you can change it via the command line parameters (see Usage).
It is possible to launch remote traces from another command line, and view the results directly in the terminal. All it takes is a compatible text browser, for example elinks
(but you can download results for later reviewing even using curl
or really anything else).
The script makes use of 8-bit ANSI colors for its output, so the command to launch a remote trace using elinks would be something like this:
elinks -dump -dump-color-mode 3 http://<ASN_SRV_IP>:49200/asn_lookup&8.8.8.8
The server logic in itself is very simple: the script implements a basic web server entirely in BASH, leveraging the fact that it can talk to a browser using the HTTP protocol and the HTML language, in a reasonably simple way.
The core behind it revolves around ncat, a very robust and stable netcat-like network tool. This is the actual "server" listening for incoming connection, and spawning connection handlers (that is, 'single-purpose' instances of the asn
script itself) as clients connect.
If you decide to open it to the outside (i.e.: binding it to something that is not localhost, and launching traces from outside your local machine), please bear in mind that there is no authentication mechanism (yet) integrated into the code, so theoretically anybody with the right URL could spawn traceroutes from your server and view the results (bear in mind however that the server sanitizes user input by stripping any dangerous characters).
To contrast that, fortunately ncat
implements a robust allow/deny logic (based both on command line parameters and files, a la /etc/hosts.allow
and hosts.deny
). The script supports passing parameters directly to ncat
, therefore it's possible to make full use of its filtering capabilities and lock the server to a restricted range of trusted IPs.
The available options, and some usage examples, can be viewed by running asn -h
.
Note: if you plan to run the server somewhere else than your local machine, remember to change the bookmarklet code and the custom search engine URL values to reflect the actual IP of the asn server. It is naturally possible to have multiple bookmarklets and search engine keywords to map to different ASN server instances.
For the bookmarklet, you'll need to change this value at the very beginning:
var asnserver="localhost:49200"
and make it point to the new address:port pair. No further change is required in the remaining JS code.
The tool can query Shodan's InternetDB API to look up informations regarding any type of targets when launched with the -s
command line switch.
If the scan identifies any vulnerabilities, the NIST NVD API is queried in order to provide descriptions, any well known names and a link to learn more about the top ones.
Currently supported targets are:
Target types can be mixed and queried in a single run. Targets can be piped to the tool via standard input as well.
Usage Examples:
asn -s 1.1.1.1 8.8.8.8 9.9.9.9
asn -s https://www.google.com 8.8.8.0/24
asn -s < iplist
curl -s https://raw.githubusercontent.com/firehol/blocklist-ipsets/master/blocklist_de_bots.ipset | asn -s
Shodan scan results can be output in JSON mode by passing the -j
or -J
options.
Note: the Nmap tool is needed to use this feature, but note that no packets whatsoever are sent to the targets. Nmap is only required to break down CIDR blocks into single IPs (as a calculator tool).
The tool will search and display all IPv4 and IPv6 CIDR blocks allocated to a specific country when launched with the -c
command line switch, plus some statistics.
.fr
) will yield direct results for France, while full text search will display country codes matching the search string, or proceed to display the results if only one match is found.Usage Examples:
asn -c germany
asn -c .de
# scan a random norwegian subnet for CVE/CPE/open ports/hostnames:
asn -jc .no | jq -r ".results[] | .ipv4[$RANDOM % .ipv4_blocks]" | asn -s
In this mode the tool will extract all IPv4 and IPv6 addresses from the input data and geolocate them. Anycast detection and general stats (top IPv4/IPv6 addresses with number of occurrences, number of IPs per country etc.) are included in the output. Bulk geolocation is quicker than normal asn
lookups (300 IP addresses can be parsed in ~5s), and its main use case is to extract, geolocate and calculate country/occurrence stats for any number of IPs from arbitrarily formatted data streams (e.g. server logs). JSON output and stdin input are supported.
Usage Examples:
asn -g 1.1.1.1 8.8.8.8
# geolocate webserver clients
asn -g < /var/log/apache2/access.log
# geolocate IPs that have logged in to the system
last | asn -g
The tool can be instructed to output lookup results in JSON mode by using the -j
(compact JSON) or -J
(pretty-printed JSON) command line options:
##### Command: `asn -J 8.8.8.8` ##### Output: ```json { "target": "8.8.8.8", "target_type": "ipv4", "result": "ok", "reason": "success", "version": "0.78.0", "request_time": "2024-08-20T02:50:28", "request_duration": 5, "api_tokens": { "ipqualityscore": true, "ipinfo": true, "cloudflare": true }, "result_count": 1, "results": [ { "ip": "8.8.8.8", "ip_version": "4", "reverse": "dns.google", "org_name": "Google LLC", "net_range": "8.8.8.0/24", "net_name": "GOGL", "abuse_contacts": [ "network-abuse@google.com" ], "routing": { "is_announced": true, "as_number": "15169", "as_name": "GOOGLE, US", "as_rank": "1788", "route": "8.8.8.0/24", "route_name": "", "roa_count": "1", "roa_validity": "valid" }, "type": { "is_bogon": false, "is_anycast": true, "is_mobile": false, "is_proxy": false, "is_dc": true, "dc_details": { "dc_name": "Google LLC" }, "is_ixp": false }, "geolocation": { "city": "Mountain View", "region": "California", "country": "United States", "cc": "US" }, "reputation": { "status": "good", "is_known_good": true, "known_as": "Google Public DNS" }, "fingerprinting": { "ports": [ 53, 443 ] } } ] } ```
##### Command: `asn -J 5505` ##### Output: ```json { "target": "5505", "target_type": "asn", "result": "ok", "reason": "success", "version": "0.78.0", "request_time": "2024-08-20T02:50:46", "request_duration": 17, "api_tokens": { "ipqualityscore": true, "ipinfo": true, "cloudflare": true }, "result_count": 1, "results": [ { "asn": "5505", "asname": "VADAVO, ES", "asrank": 4448, "org": "VDV-VLC-RED06 VDV-VLC-RED06 - CLIENTES TELECOM", "holder": "VADAVO SOLUCIONES SL", "abuse_contacts": [ "abuse@vadavo.com" ], "registration_date": "2016-12-13T08:28:07", "ixp_presence": [ "DE-CIX Madrid: DE-CIX Madrid Peering LAN", "ESpanix Madrid Lower LAN" ], "prefix_count_v4": 8, "prefix_count_v6": 1, "bgp_peer_count": 36, "bgp_hijack_incidents": { "total": 0, "as_hijacker": 0, "as_victim": 0 }, "bgp_leak_incidents": { "total": 0 }, "bgp_peers": { "upstream": [ "1299", "6939", "59432", "174", "34549", "25091", "35625", "33891", "48348", "13030", "8218", "41327", "3303", "4455", "6424", "6057", "34927", "9498", "35280", "1239" ], "downstream": [ "48952", "208248", "205086", "202054" ], "uncertain": [ "24482", "51185", "41047", "29680", "212483", "198150", "14840", "49544", "39384", "37721", "36236", "25160" ] }, "announced_prefixes": { "v4": [ "185.210.225.0/24", "188.130.247.0/24", "185.210.227.0/24", "185.123.205.0/24", "185.123.207.0/24", "185.210.226.0/24", "185.123.206.0/24", "185.123.204.0/24" ], "v6": [ "2a03:9320::/32" ] }, "inetnums": { "v4": [ "185.123.204.0/22", "185.210.225.0/24", "185.210.226.0/24", "185.210.227.0/24", "188.130.247.0/24" ], "v6": [ "2a03:9320::/32" ] }, "inetnums_announced_by_other_as": { "v4": [ { "prefix": "188.130.254.0/24", "origin_asn": "", "origin_org": "", "is_announced": false } ], "v6": [] } } ] } ```
##### Command: `asn -j www.google.com | jq '[.results[].abuse_contacts[]] | unique[]'` ##### Output: ``` "network-abuse@google.com" "ripe-contact@google.com" ```
##### Command: `asn -j 45.67.34.100 | jq '.results[].fingerprinting.vulns[]'` ##### Output: ``` "CVE-2017-15906" "CVE-2018-15919" ```
##### Command: `asn -Ju 72.17.119.201` ##### Output: ```json { "target": "72.17.119.201", "target_type": "ipv4", "result": "ok", "reason": "success", "version": "0.78.0", "request_time": "2024-08-20T02:54:03", "request_duration": 4, "api_tokens": { "ipqualityscore": true, "ipinfo": true, "cloudflare": true }, "result_count": 1, "results": [ { "prefix": "72.17.0.0/17", "origin_as": "33363", "origin_as_name": "BHN-33363, US", "origin_as_rank": 441, "upstreams_count": 1, "upstreams": [ { "asn": "7843", "asname": "TWC-7843-BB, US", "probability": 100, "is_tier1": false } ], "multiple_upstreams": false } ] } ```
##### Command: `asn -j AS5505 | jq -r '.results[].inetnums_announced_by_other_as.v4[] | select(.is_announced==false) | .prefix'` ##### Output: ``` 188.130.254.0/24 ```
##### Command: `asn -j AS8860 | jq '.results[].bgp_hijack_incidents'` ##### Output: ``` { "total": 18, "as_hijacker": 11, "as_victim": 7 } ```
By running the script in server mode, it is possible to use it as a self-hosted lookup API service by running HTTP queries against it and retrieving the results in compact or pretty-printed JSON format. The server exposes the asn_lookup_json
and asn_lookup_jsonp
endpoints for this purpose. The syntax is the same as with normal browser-based remote queries.
Example 1: querying the server remotely using curl
(compact output):
root@KRUSTY:~# curl -s "http://localhost:49200/asn_lookup_json&1.1.1.1"
{"target":"1.1.1.1","target_type":"ipv4","result":"ok","reason":"success","version":"0.72.1","request_time":"2022-03-29T00:13:11","request_duration":5,"result_count":1,"results":[{"ip":"1.1.1.1","ip_version":"4","reverse":"one.one.one.one","org_name":"APNIC and Cloudflare DNS Resolver project","abuse_contacts":["helpdesk@apnic.net"],"routing":{"is_announced":true,"as_number":"13335","as_name":"CLOUDFLARENET, US","net_range":"1.1.1.0/24","net_name":"APNIC-LABS","roa_count":"1","roa_validity":"valid"},"type":{"is_bogon":false,"is_anycast":true,"is_mobile":false,"is_proxy":false,"is_dc":true,"dc_details":{"dc_name":"Cloudflare"},"is_ixp":false},"geolocation":{"city":"Magomeni","region":"Dar es Salaam","country":"Tanzania","cc":"TZ"},"reputation":{"status":"good","is_known_good":true,"known_as":"Cloudflare Public DNS"},"fingerprinting":{"ports":[53,80,443]}}]}
Example 2: querying the server remotely using curl
(pretty printed output):
root@KRUSTY:~# curl -s "http://localhost:49200/asn_lookup_jsonp&10.0.0.1"
{
"target": "10.0.0.1",
"target_type": "ipv4",
"result": "ok",
"reason": "success",
"version": "0.72.1",
"request_time": "2022-03-29T00:14:57",
"request_duration": 0,
"result_count": 1,
"results": [
{
"ip": "10.0.0.1",
"ip_version": "4",
"org_name": "IANA",
"routing": {
"is_announced": false,
"net_name": "PRIVATE-ADDRESS-ABLK-RFC1918-IANA-RESERVED"
},
"type": {
"is_bogon": true,
"bogon_type": "rfc1918 (Private Space)"
},
"reputation": {},
"fingerprinting": {}
}
]
}
An initial version of this script was featured in the Security Trails blog post "ASN Lookup Tools, Strategies and Techniques". Thank you Esteban!
Thanks Massimo Candela for your support and excellent work on IPmap, BGPlay and TraceMON!
Thanks to all the awesome contributors for their code, ideas, suggestions, packages and bug reports!
Any feedback or pull request to improve the code is welcome. Feel free to contribute!