Difference between revisions of "ARG Toolbox"

Revision as of 12:15, 13 September 2023

Main Page > List of Investigations > ARG Toolbox

This page is an archive of helpful tools and resources one might use in the course of solving puzzles typically found in ARGs, including encipher/deciphering, audio encoding, and steganography.

ARG Training

Academy

https://gamedetectives.net/academy/

A series of challenges meant to teach to basic elements, techniques, and dynamics of ARGs, made in-house by the Game Detectives.

ae27ff

http://ae27ff.challenge.pt/

ae27ff is a series of puzzles that use the typical techniques of most ARGs. They get more difficult the higher you go. Made by Discord user crashdemons.

ARGvent

http://gamedetectives.net/argvent/

An annual Game Detectives tradition consisting of a series of puzzles unlocking each day over advent, with varying difficulty. Created by the GameDetectives admins.

Enigma Group

https://www.enigmagroup.org

A puzzle site that has many categories of learning. They begin as really easy, but then ascend to a more difficult encounter.

Levels

http://levels.your-host.xyz/

A series of puzzles designed to introduce people to ARG solving. They range from easy to very hard. Levels can be gained through active participation on the official forum.

Last transmision

http://last.boxfish.ink

A short, interactive, slightly creepy story made by Discord user mai(#9088). Will put your basic puzzle solving skills to the test.

Watching You

https://stvjsmrs.wordpress.com/

Originally forming part of an ARG, the site now houses two series of puzzles - the originals, and a cancelled Advent version. Made by Discord users in Team Look In The Bushes.

Text-based Tools

Decodes ascii85 messages. (there's a version for encoding as well)

asciitohex

http://www.asciitohex.com/

Converts ASCII to hex and vice versa, as well as to other number-based encryption methods.

Ave Maria Cipher

http://de.wikipedia.org/w/index.php?title=Datei:Trithemius-Polygraphiae-71.jpg

Ave Maria cipher.

Browserling

https://www.browserling.com/tools/

Lots of encodings and encryptions.

Chaffing & Winnowing

http://en.wikipedia.org/wiki/Chaffing_and_winnowing http://people.csail.mit.edu/rivest/Chaffing.txt

Everything you need to know about Chaffing and winnowing.

Cryptii

https://cryptii.com/text/text

Site with a lot of ciphers.

CryptoCrack

https://sites.google.com/site/cryptocrackprogram/

Has a lot of classical ciphers and more.

Cryptomathic

http://extranet.cryptomathic.com

EMV tag search. TLV (Tag, Length, Value) byte strings into their constituent tags and sub-tags. Useful for analysing APDU traces, responses and so on. CAP calculator. Features many more features.

Cryptool-Online

http://www.cryptool-online.org

Features enciphering (enigma, navajo, vigenere), encoding (ASCII, Code39, Huffman), text analysis, etc.

Crypto-Tools

https://github.com/Hegz/crypto-tools

Set of crypto-tools.

CyberChef

https://gchq.github.io/CyberChef/

MULTIPLE methods of enciphering/encoding, uses more complicated methods and can have more processes going on at once.

Darkfader

https://www.darkfader.net/toolbox/convert/

Online conversion utilities.

Dcode

http://www.dcode.fr/tools-list

Contains a list of mathematical problem calculations, encodings, encryptions, and many more.

HTTP Referer Extension

LEGACY FIREFOX: https://addons.mozilla.org/En-US/firefox/addon/refcontrol/

QUANTUM: https://addons.mozilla.org/en-US/firefox/addon/referer-modifier/

CHROME: https://chrome.google.com/webstore/detail/referer-control/hnkcfpcejkafcihlgbojoidoihckciin?hl=es-419

Extensions for Legacy Firefox, Quantum and Chrome to help modifying HTTP referers.

Iterative Anagram Solver

http://boulter.com/anagram/

Decodes multi-word anagrams word by word.

Kryptographiespielplatz

https://www.kryptographiespielplatz.de/index.php?

List of a lot of ciphers. (It's in German, but common sense is enough. Test them out on the part where it says [ausprobieren]

Link Identifier

https://a4x.me/tools/link/

A tool that will guess what site a link identifier could belong to given the length. Made by Discord user A4.

Linux Command Line Encode / Decode

http://technet.microsoft.com/en-us/sysinternals/bb897439.aspx

Use linux command line strings to encode and decode.

md5hashing

https://md5hashing.net/hash_type_checker

Allows you to decode many variations of MD5 and Sha ciphers.

Omniglot Conscripts

http://www.omniglot.com/conscripts/english.htm

Has a list of alternate fonts that can be used for writing english.

OPENPGP

http://openpgp.org/software/

PGP and GPG downloads.

PharmaBraille

https://www.pharmabraille.com/pharmaceutical-braille/the-braille-alphabet/

Contains a detailed list of the Braille alphabet, including numbers and punctuation.

Polygraphic Substitution Systems

http://www.umich.edu/~umich/fm-34-40-2/ch7.pdf

Breaking polygraphic substitution systems.

RICHKNI

http://www.richkni.co.uk/php/crypta/freq.php

Word frequency analysis, can be really useful for substitution ciphers with no key.

Rumkin

http://rumkin.com/tools/cipher/

Contains big list of ciphers.

SNOW Whitespace

http://www.darkside.com.au/snow/

Whitespace steganography.

SpamMimic

http://spammimic.com/

Hides a message in what appears to be a harmless block of spam.

The Black Chamber

http://www.simonsingh.net/The_Black_Chamber/chamberguide.html

Has a set of text enciphering and encoding methods.

WeChall Encryption tools.

https://www.wechall.net/tools/

Features JPocketKnife, a conversion tool, JDicTac, a bruteforce for homemade ciphers and hashes, etc.

Wikibruce

http://ref.wikibruce.com/hub

For text encryption, it features ROT-n, Hexadecimal, Binary, ASCII, Morse, Pattern Recognition, and separating byte data to 8 bit planes.

Xlate

http://cyber.meme.tips/xlate

Multiple methods of encoding, including a personalized radix, or base, decoding. (Supports Base 2 - 36)

XOR / Byte Shift

http://otp22.com/xlate/shifts.html

Is used to show all 255 XOR and Byte Shift instances.

Audio Analysis

Audacity

https://www.audacityteam.org/

Useful program used for audio inspecting.

Direwolf

https://github.com/wb2osz/direwolf

Software "soundcard" AX.25 packet modem/TNC and APRS encoder/decoder. It can be used stand-alone to observe APRS traffic, as a tracker, digipeater, APRStt gateway, or Internet Gateway (IGate).

NOTE: Not user-friendly!

DTMF

http://www.teworks.com/dtmf.htm

Dual Tone Multi Frequency tones decoding.

fldigi

https://sourceforge.net/projects/fldigi/ (fldigi)

Can encrypt/decrypt a lot of audio encryption. Manual can be found here.

NOTE: Not user-friendly!

Ham Radio Directory Downloads

https://radio.linux.org.au/?sectpat=digital

Includes 35 ham radio tools.

NOTE: It may not work on certain OS, and not all of them are user-friendly.

Kansas City Standard Cassette Audio Data

http://www.dabeaz.com/py-kcs/index.html

Can be used to encode/decode Kansas City Standard Cassette Audio Data.

MM-SSTV

http://hamsoft.ca/pages/mmsstv.php

Slow Scan Television Program. Alternative to RXSSTV.

OTP22 Signal Decoders

https://github.com/otp22/decoders

Directory for multiple methods of encryption used in otp22, ABISM tone decodings (Modified ASCII tones), NATO 5gram decoder, and another XOR program.

RX-SSTV

http://users.belgacom.net/hamradio/rxsstv.htm

A program that deciphers SSTV encryption on audio tracks.

SonicVisualiser

http://sonicvisualiser.org/

Creates spectographs of audio.

Sorcerer

http://www.kd0cq.com/2013/07/sorcerer-decoder-download/

Has more radio recieving modes than fldigi, like Harris RF-3560 PSTN TIU,IRA-ARQ (ASCII-ARQ), etc. (only for decoding)

Wavepad FFT

http://www.nch.com.au/wavepad/fft.html

Audio spectogram analysis.

Image Analysis

Binvis

http://binvis.io/#/

Gives a visual representation of binary files.

Ceefax

http://edit.tf/

Can be used to upload ceefax images.

EXIF

http://exif.regex.info/exif.cgi

Used to find EXIF data and ID3 tags.

Futureboy

https://futureboy.us/stegano/

Allows to compare the differences of two images, and unlock steganography with passwords.

GIMP

https://www.gimp.org/downloads/

Free program. Alternative to photoshop. Can export and import raw files.

JHead

http://mirror.otp22.com/jhead

Allows for the viewing of jpeg headers, abnormalities, and outgress output.

Magic Eyes

http://magiceye.ecksdee.co.uk/ To solve magic eyes

http://www.easystereogrambuilder.com/3d-stereogram-maker.aspx To make them.

Nonograms

http://nonomaker.com/ Used to make nonograms aaaaand

http://a.teall.info/nonogram/ to solve them.

Outguess

http://filehippo.com/mac/download_outguess/

Outguess steganography.

NOTE: Only works on mac. Try using a virtual machine for opening it.

Photo Forensics

https://29a.ch/photo-forensics/#forensic-magnifier

Magnifier, clone detection, error level analysis, and more tools.

Pixlr

http://pixlr.com/editor/

Online GIMP-style editor.

Punchcards

http://www.kloth.net/services/cardpunch.php

Punchcards simulator.

QR Codes

http://www.qrcode-generator.de/ and https://dnschecker.org/qr-code-generator.php For making QR codes.

https://webqr.com/ and https://dnschecker.org/qr-code-scanner.php For reading QR codes.

Rawpixels

http://rawpixels.net/

Visualizes .raw files.

Tinkercad

https://www.tinkercad.com/

Web-based 3D modeling.

WeChall Tools

https://www.wechall.net/tools/

Features JColorSucker to grab pixel values from images.

Wikibruce

http://ref.wikibruce.com/hub

For image steganography, wikibruse can submit delimited list of pixel bytes. Resulting file is a single plane greyscale PNG. (eg: 255,0,255,0,255,0,0,255,0 with width 3)

General Steganography / Tools

Hex Editors

https://hexed.it/

Online hex editor.

https://mh-nexus.de/en/hxd/

Offline hex editor (has more utilities).

http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm

Another Offline hex editor but without needing to install it and has scripting.

HTTP referrers

https://addons.mozilla.org/En-US/firefox/addon/refcontrol/

Firefox extension to find HTTP referrers.

Notepad++

https://notepad-plus-plus.org

VERY useful program. Similar to Notepad but has many more utilities.

OtpXor

https://github.com/otp22/decoders/tree/master/OtpXor

Made by the creator of ae27ff, allows for the xoring of two large files together.

Repl

https://repl.it/

Website used to run and debug code.

XorJ

https://github.com/crashdemons/XorJ

Made by the creator of ae27ff, allows for the xoring of two relatively small files together.

@@ Line 1: / Line 1: @@
+{{argHeader}}
+{{backToTop}}
+This page is an archive of helpful tools and resources one might use in the course of solving puzzles typically found in ARGs, including encipher/deciphering, audio encoding, and steganography.
-=Tools=
+__TOC__
-==Cipher Solving Tools==
+==ARG Training==
+===Academy===
+https://gamedetectives.net/academy/
+A series of challenges meant to teach to basic elements, techniques, and dynamics of ARGs, made in-house by the Game Detectives.
+===ae27ff===
+http://ae27ff.challenge.pt/
+ae27ff is a series of puzzles that use the typical techniques of most ARGs. They get more difficult the higher you go. Made by Discord user crashdemons.
+===ARGvent===
+http://gamedetectives.net/argvent/
+An annual Game Detectives tradition consisting of a series of puzzles unlocking each day over advent, with varying difficulty. Created by the GameDetectives [[Meta:Staff|admins]].
+===Enigma Group===
+https://www.enigmagroup.org
+A puzzle site that has many categories of learning. They begin as really easy, but then ascend to a more difficult encounter.
+===Levels===
+http://levels.your-host.xyz/
+A series of puzzles designed to introduce people to ARG solving. They range from easy to very hard. Levels can be gained through active participation on the official forum.
+===Last transmision===
+http://last.boxfish.ink
+A short, interactive, slightly creepy story made by Discord user mai(#9088). Will put your basic puzzle solving skills to the test.
+===Watching You===
+https://stvjsmrs.wordpress.com/
+Originally forming part of an [[Watching You:Timeline|ARG]], the site now houses two series of puzzles - the originals, and a cancelled Advent version. Made by Discord users in Team Look In The Bushes.
+==Text-based Tools==
+===Anagrams===
+http://anagramscramble.com/                                                     Word de-scrambler
+http://textmechanic.com/text-tools/obfuscation-tools/word-scramblerunscrambler/ Word scrambler
+===Missing letters solver===
+https://www.unscramblerer.com/crossword-solver/
+===Ascii85===
+https://www.tools4noobs.com/online_tools/ascii85_decode/
+Decodes ascii85 messages. (there's a version for encoding as well)
+===asciitohex===
+http://www.asciitohex.com/
+Converts ASCII to hex and vice versa, as well as to other number-based encryption methods.
+===Ave Maria Cipher===
+http://de.wikipedia.org/w/index.php?title=Datei:Trithemius-Polygraphiae-71.jpg
+Ave Maria cipher.
+===Browserling===
+https://www.browserling.com/tools/
+Lots of encodings and encryptions.
+===Chaffing & Winnowing===
+http://en.wikipedia.org/wiki/Chaffing_and_winnowing
+http://people.csail.mit.edu/rivest/Chaffing.txt
+Everything you need to know about Chaffing and winnowing.
+===Cryptii===
+https://cryptii.com/text/text
+Site with a lot of ciphers.
+===CryptoCrack===
+https://sites.google.com/site/cryptocrackprogram/
+Has a lot of classical ciphers and more.
+===Cryptomathic===
+http://extranet.cryptomathic.com
+EMV tag search. TLV (Tag, Length, Value) byte strings into their constituent tags and sub-tags. Useful for analysing APDU traces, responses and so on. CAP calculator. Features many more features.
+===Cryptool-Online===
+http://www.cryptool-online.org
+Features enciphering (enigma, navajo, vigenere), encoding (ASCII, Code39, Huffman), text analysis, etc.
+===Crypto-Tools===
+https://github.com/Hegz/crypto-tools
+Set of crypto-tools.
+===CyberChef===
-* Cyberchef:
 https://gchq.github.io/CyberChef/
-Includes tools to decipher B64, MD5, and other related hashes.
+MULTIPLE methods of enciphering/encoding, uses more complicated methods and can have more processes going on at once.
+===Darkfader===
+https://www.darkfader.net/toolbox/convert/
+Online conversion utilities.
+===Dcode===
+http://www.dcode.fr/tools-list
+Contains a list of mathematical problem calculations, encodings, encryptions, and many more.
+===HTTP Referer Extension===
+'''LEGACY FIREFOX''': https://addons.mozilla.org/En-US/firefox/addon/refcontrol/
+'''QUANTUM''': https://addons.mozilla.org/en-US/firefox/addon/referer-modifier/
+'''CHROME''': https://chrome.google.com/webstore/detail/referer-control/hnkcfpcejkafcihlgbojoidoihckciin?hl=es-419
+Extensions for Legacy Firefox, Quantum and Chrome to help modifying HTTP referers.
+===Iterative Anagram Solver===
+http://boulter.com/anagram/
+Decodes multi-word anagrams word by word.
+===Kryptographiespielplatz===
+https://www.kryptographiespielplatz.de/index.php?
+List of a lot of ciphers. (It's in German, but common sense is enough.
+Test them out on the part where it says [ausprobieren]
+===Link Identifier===
+https://a4x.me/tools/link/
+A tool that will guess what site a link identifier could belong to given the length. Made by Discord user A4.
+===Linux Command Line Encode / Decode===
+http://technet.microsoft.com/en-us/sysinternals/bb897439.aspx
+Use linux command line strings to encode and decode.
+===md5hashing===
+https://md5hashing.net/hash_type_checker
+Allows you to decode many variations of MD5 and Sha ciphers.
+===Omniglot Conscripts===
+http://www.omniglot.com/conscripts/english.htm
+Has a list of alternate fonts that can be used for writing english.
+===OPENPGP===
+http://openpgp.org/software/
+PGP and GPG downloads.
+===PharmaBraille===
+https://www.pharmabraille.com/pharmaceutical-braille/the-braille-alphabet/
+Contains a detailed list of the Braille alphabet, including numbers and punctuation.
+===Polygraphic Substitution Systems===
+http://www.umich.edu/~umich/fm-34-40-2/ch7.pdf
+Breaking polygraphic substitution systems.
+===RICHKNI===
+http://www.richkni.co.uk/php/crypta/freq.php
+Word frequency analysis, can be really useful for substitution ciphers with no key.
+===Rumkin===
+http://rumkin.com/tools/cipher/
+Contains big list of ciphers.
+===SNOW Whitespace===
+http://www.darkside.com.au/snow/
+Whitespace steganography.
+===SpamMimic===
+http://spammimic.com/
+Hides a message in what appears to be a harmless block of spam.
+===The Black Chamber===
+http://www.simonsingh.net/The_Black_Chamber/chamberguide.html
+Has a set of text enciphering and encoding methods.
+===WeChall Encryption tools.===
+https://www.wechall.net/tools/
+Features JPocketKnife, a conversion tool, JDicTac, a bruteforce for homemade ciphers and hashes, etc.
+===Wikibruce===
+http://ref.wikibruce.com/hub
+For text encryption, it features ROT-n, Hexadecimal, Binary, ASCII, Morse, Pattern Recognition, and separating byte data to 8 bit planes.
+===Xlate===
+http://cyber.meme.tips/xlate
+Multiple methods of encoding, including a personalized radix, or base, decoding. (Supports Base 2 - 36)
+===XOR / Byte Shift===
+http://otp22.com/xlate/shifts.html
+Is used to show all 255 XOR and Byte Shift instances.
+==Audio Analysis==
+===Audacity===
+https://www.audacityteam.org/
+Useful program used for audio inspecting.
+===Direwolf===
+https://github.com/wb2osz/direwolf
+Software "soundcard" AX.25 packet modem/TNC and APRS encoder/decoder. It can be used stand-alone to observe APRS traffic, as a tracker, digipeater, APRStt gateway, or Internet Gateway (IGate).
+*NOTE: Not user-friendly!
+===DTMF===
+http://www.teworks.com/dtmf.htm
+Dual Tone Multi Frequency tones decoding.
+===fldigi===
+https://sourceforge.net/projects/fldigi/ (fldigi)
+Can encrypt/decrypt a lot of audio encryption.
+Manual can be found [http://cyber.meme.tips/fldigi-guide here.]
+*NOTE: Not user-friendly!
+===Ham Radio Directory Downloads===
+https://radio.linux.org.au/?sectpat=digital
+Includes 35 ham radio tools.
+*NOTE: It may not work on certain OS, and not all of them are user-friendly.
+===Kansas City Standard Cassette Audio Data===
+http://www.dabeaz.com/py-kcs/index.html
+Can be used to encode/decode Kansas City Standard Cassette Audio Data.
+===MM-SSTV===
+http://hamsoft.ca/pages/mmsstv.php
+Slow Scan Television Program. Alternative to RXSSTV.
+===OTP22 Signal Decoders===
+https://github.com/otp22/decoders
+Directory for multiple methods of encryption used in otp22, ABISM tone decodings (Modified ASCII tones), NATO 5gram decoder, and another XOR program.
+===RX-SSTV===
+http://users.belgacom.net/hamradio/rxsstv.htm
+A program that deciphers SSTV encryption on audio tracks.
+===SonicVisualiser===
+http://sonicvisualiser.org/
+Creates spectographs of audio.
+===Sorcerer===
+http://www.kd0cq.com/2013/07/sorcerer-decoder-download/
+Has more radio recieving modes than fldigi, like Harris RF-3560 PSTN TIU,IRA-ARQ (ASCII-ARQ), etc. (only for decoding)
+===Wavepad FFT===
+http://www.nch.com.au/wavepad/fft.html
+Audio spectogram analysis.
+==Image Analysis==
+===Binvis===
+http://binvis.io/#/
+Gives a visual representation of binary files.
+===Ceefax===
+http://edit.tf/
+Can be used to upload ceefax images.
+===EXIF===
+http://exif.regex.info/exif.cgi
+Used to find EXIF data and ID3 tags.
+===Futureboy===
+https://futureboy.us/stegano/
+Allows to compare the differences of two images, and unlock steganography with passwords.
+===GIMP===
+https://www.gimp.org/downloads/
+Free program. Alternative to photoshop. Can export and import raw files.
+===JHead===
+http://mirror.otp22.com/jhead
+Allows for the viewing of jpeg headers, abnormalities, and outgress output.
+===Magic Eyes===
+http://magiceye.ecksdee.co.uk/                                To solve magic eyes
+http://www.easystereogrambuilder.com/3d-stereogram-maker.aspx To make them.
+===Nonograms===
+http://nonomaker.com/  Used to make nonograms aaaaand
+http://a.teall.info/nonogram/ to solve them.
+===Outguess===
+http://filehippo.com/mac/download_outguess/
+Outguess steganography.
+*NOTE: Only works on mac. Try using a virtual machine for opening it.
+===Photo Forensics===
+https://29a.ch/photo-forensics/#forensic-magnifier
+Magnifier, clone detection, error level analysis, and more tools.
+===Pixlr===
+http://pixlr.com/editor/
+Online GIMP-style editor.
+===Punchcards===
+http://www.kloth.net/services/cardpunch.php
+Punchcards simulator.
+===QR Codes===
+http://www.qrcode-generator.de/ and https://dnschecker.org/qr-code-generator.php  For making QR codes.
+https://webqr.com/  and https://dnschecker.org/qr-code-scanner.php            For reading QR codes.
+===Rawpixels===
+http://rawpixels.net/
+Visualizes .raw files.
+===Tinkercad===
+https://www.tinkercad.com/
+Web-based 3D modeling.
+===WeChall Tools===
+https://www.wechall.net/tools/
+Features JColorSucker to grab pixel values from images.
+===Wikibruce===
+http://ref.wikibruce.com/hub
+For image steganography, wikibruse can submit delimited list of pixel bytes. Resulting file is a single plane greyscale PNG. (eg: 255,0,255,0,255,0,0,255,0 with width 3)
+==General Steganography / Tools==
+===Hex Editors===
+https://hexed.it/
+*Online hex editor.
+https://mh-nexus.de/en/hxd/
+*Offline hex editor (has more utilities).
+http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm
+*Another Offline hex editor but without needing to install it and has scripting.
+===HTTP referrers===
+https://addons.mozilla.org/En-US/firefox/addon/refcontrol/
+Firefox extension to find HTTP referrers.
+===Notepad++===
+https://notepad-plus-plus.org
+VERY useful program. Similar to Notepad but has many more utilities.
+===OtpXor===
+https://github.com/otp22/decoders/tree/master/OtpXor
+Made by the creator of ae27ff, allows for the xoring of two large files together.
+===Repl===
+https://repl.it/
+Website used to run and debug code.
+===XorJ===
+https://github.com/crashdemons/XorJ
+Made by the creator of ae27ff, allows for the xoring of two relatively small files together.

Difference between revisions of "ARG Toolbox"

Revision as of 12:15, 13 September 2023

Contents

ARG Training

Academy

ae27ff

ARGvent

Enigma Group

Levels

Last transmision

Watching You

Text-based Tools

Anagrams

Missing letters solver

Ascii85

asciitohex

Ave Maria Cipher

Browserling

Chaffing & Winnowing

Cryptii

CryptoCrack

Cryptomathic

Cryptool-Online

Crypto-Tools

CyberChef

Darkfader

Dcode

HTTP Referer Extension

Iterative Anagram Solver

Kryptographiespielplatz

Link Identifier

Linux Command Line Encode / Decode

md5hashing

Omniglot Conscripts

OPENPGP

PharmaBraille

Polygraphic Substitution Systems

RICHKNI

Rumkin

SNOW Whitespace

SpamMimic

The Black Chamber

WeChall Encryption tools.

Wikibruce

Xlate

XOR / Byte Shift

Audio Analysis

Audacity

Direwolf

DTMF

fldigi

Ham Radio Directory Downloads

Kansas City Standard Cassette Audio Data

MM-SSTV

OTP22 Signal Decoders

RX-SSTV

SonicVisualiser

Sorcerer

Wavepad FFT

Image Analysis

Binvis

Ceefax

EXIF

Futureboy

GIMP

JHead

Magic Eyes

Nonograms

Outguess

Photo Forensics

Pixlr

Punchcards

QR Codes

Rawpixels

Tinkercad

WeChall Tools

Wikibruce

General Steganography / Tools

Hex Editors

HTTP referrers