Rating:
Black Hole
========
> John Hammond | Tuesday, February 7th, 2017
--------------------------------------------
> We are trying to study the Black Holes. One of the most controversial theory related to Black Holes is the "Information Loss Paradox". Calculations suggest that physical information could permanently disappear in a black hole. But this violates the quantum theory. To test the hypothesis, we sent our flag encoded in Base64 format towards a Black Hole. With the help of our Hubble Space Telescope, we got some pictures of the Black Hole. See if you can recover the flag from this information.
We are given [this image](black_hole.jpg) to work with.
This was the first forensics problem, with only 10 points, so I thought it should be pretty easy. I tried a lot of the low-hanging fruit until I realized what was up.
The challenge prompt really insisted "we sent our flag encoded in [base64] format towards a black hole"... and when I ran [`strings`][strings], I found something that really looked like [base64] but I couldn't get it to decode.
```
strings black_hole.jpg
...
UQklUQ1RGe1M1IDAwMTQrODF9
...
```
That definitely looked like [base64], so I tried it, but it failed, no matter how much [padding] I tried to tack on.
``` python
>>> import base64
>>> base64.b64decode('UQklUQ1RGe1M1IDAwMTQrODF9')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/base64.py", line 78, in b64decode
raise TypeError(msg)
TypeError: Incorrect padding
```
What the heck? Was this a red-herring?
After my banging my head against the wall for a long while, I eventually told myself it _had_ to be the flag.
So, I tried the opposite: I tried to _encode_ what the flag should look like, I tried to [base64] encode the starting flag format.
``` python
>>> base64.b64encode('BITSCTF')
'QklUU0NURg=='
```
_That looks really similar to what we have..._
___Oh! The starting "U" is out of place, it shouldn't be there!___
Maybe that came from another random string, or whatever. But I tried to remove that 'U' and decode again...
``` python
>>> base64.b64decode('QklUQ1RGe1M1IDAwMTQrODF9')
'BITCTF{S5 0014+81}'
```
Aha! __Win.__
__The flag was: `BITCTF{S5 0014+81}`__
[netcat]: https://en.wikipedia.org/wiki/Netcat
[Wikipedia]: https://www.wikipedia.org/
[Linux]: https://www.linux.com/
[man page]: https://en.wikipedia.org/wiki/Man_page
[man pages]: https://en.wikipedia.org/wiki/Man_page
[man]: https://en.wikipedia.org/wiki/Man_page
[PuTTY]: http://www.putty.org/
[ssh]: https://en.wikipedia.org/wiki/Secure_Shell
[Windows]: http://www.microsoft.com/en-us/windows
[virtual machine]: https://en.wikipedia.org/wiki/Virtual_machine
[operating system]:https://en.wikipedia.org/wiki/Operating_system
[OS]: https://en.wikipedia.org/wiki/Operating_system
[VMWare]: http://www.vmware.com/
[VirtualBox]: https://www.virtualbox.org/
[hostname]: https://en.wikipedia.org/wiki/Hostname
[port number]: https://en.wikipedia.org/wiki/Port_%28computer_networking%29
[port]: https://en.wikipedia.org/wiki/Port_%28computer_networking%29
[ports]: https://en.wikipedia.org/wiki/Port_%28computer_networking%29
[distribution]:https://en.wikipedia.org/wiki/Linux_distribution
[Ubuntu]: http://www.ubuntu.com/
[ISO]: https://en.wikipedia.org/wiki/ISO_image
[standard streams]: https://en.wikipedia.org/wiki/Standard_streams
[standard output]: https://en.wikipedia.org/wiki/Standard_streams
[standard input]: https://en.wikipedia.org/wiki/Standard_streams
[read]: http://ss64.com/bash/read.html
[variable]: https://en.wikipedia.org/wiki/Variable_%28computer_science%29
[command substitution]: http://www.tldp.org/LDP/abs/html/commandsub.html
[permissions]: https://en.wikipedia.org/wiki/File_system_permissions
[redirection]: http://www.tldp.org/LDP/abs/html/io-redirection.html
[redirect]: http://www.tldp.org/LDP/abs/html/io-redirection.html
[pipe]: http://www.tldp.org/LDP/abs/html/io-redirection.html
[piped]: http://www.tldp.org/LDP/abs/html/io-redirection.html
[piping]: http://www.tldp.org/LDP/abs/html/io-redirection.html
[tmp]: http://www.tldp.org/LDP/Linux-Filesystem-Hierarchy/html/tmp.html
[curl]: http://curl.haxx.se/
[cl1p.net]: https://cl1p.net/
[request]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html
[POST request]: https://en.wikipedia.org/wiki/POST_%28HTTP%29
[Python]: http://python.org/
[interpreter]: https://en.wikipedia.org/wiki/List_of_command-line_interpreters
[requests]: http://docs.python-requests.org/en/latest/
[urllib]: https://docs.python.org/2/library/urllib.html
[file handling with Python]: https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files
[bash]: https://www.gnu.org/software/bash/
[Assembly]: https://en.wikipedia.org/wiki/Assembly_language
[the stack]: https://en.wikipedia.org/wiki/Stack_%28abstract_data_type%29
[register]: http://www.tutorialspoint.com/assembly_programming/assembly_registers.htm
[hex]: https://en.wikipedia.org/wiki/Hexadecimal
[hexadecimal]: https://en.wikipedia.org/wiki/Hexadecimal
[archive file]: https://en.wikipedia.org/wiki/Archive_file
[zip file]: https://en.wikipedia.org/wiki/Zip_%28file_format%29
[.zip]: https://en.wikipedia.org/wiki/Zip_%28file_format%29
[gigabytes]: https://en.wikipedia.org/wiki/Gigabyte
[GB]: https://en.wikipedia.org/wiki/Gigabyte
[GUI]: https://en.wikipedia.org/wiki/Graphical_user_interface
[Wireshark]: https://www.wireshark.org/
[FTP]: https://en.wikipedia.org/wiki/File_Transfer_Protocol
[client and server]: https://simple.wikipedia.org/wiki/Client-server
[RETR]: http://cr.yp.to/ftp/retr.html
[FTP server]: https://help.ubuntu.com/lts/serverguide/ftp-server.html
[SFTP]: https://en.wikipedia.org/wiki/SSH_File_Transfer_Protocol
[SSL]: https://en.wikipedia.org/wiki/Transport_Layer_Security
[encryption]: https://en.wikipedia.org/wiki/Encryption
[HTML]: https://en.wikipedia.org/wiki/HTML
[Flask]: http://flask.pocoo.org/
[SQL]: https://en.wikipedia.org/wiki/SQL
[and]: https://en.wikipedia.org/wiki/Logical_conjunction
[Cyberstakes]: https://cyberstakesonline.com/
[cat]: https://en.wikipedia.org/wiki/Cat_%28Unix%29
[symbolic link]: https://en.wikipedia.org/wiki/Symbolic_link
[ln]: https://en.wikipedia.org/wiki/Ln_%28Unix%29
[absolute path]: https://en.wikipedia.org/wiki/Path_%28computing%29
[CTF]: https://en.wikipedia.org/wiki/Capture_the_flag#Computer_security
[Cyberstakes]: https://cyberstakesonline.com/
[OverTheWire]: http://overthewire.org/
[Leviathan]: http://overthewire.org/wargames/leviathan/
[ls]: https://en.wikipedia.org/wiki/Ls
[grep]: https://en.wikipedia.org/wiki/Grep
[strings]: http://linux.die.net/man/1/strings
[ltrace]: http://linux.die.net/man/1/ltrace
[C]: https://en.wikipedia.org/wiki/C_%28programming_language%29
[strcmp]: http://linux.die.net/man/3/strcmp
[access]: http://pubs.opengroup.org/onlinepubs/009695399/functions/access.html
[system]: http://linux.die.net/man/3/system
[real user ID]: https://en.wikipedia.org/wiki/User_identifier
[effective user ID]: https://en.wikipedia.org/wiki/User_identifier
[brute force]: https://en.wikipedia.org/wiki/Brute-force_attack
[brute-force]: https://en.wikipedia.org/wiki/Brute-force_attack
[for loop]: https://en.wikipedia.org/wiki/For_loop
[bash programming]: http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html
[Behemoth]: http://overthewire.org/wargames/behemoth/
[command line]: https://en.wikipedia.org/wiki/Command-line_interface
[command-line]: https://en.wikipedia.org/wiki/Command-line_interface
[cli]: https://en.wikipedia.org/wiki/Command-line_interface
[PHP]: https://php.net/
[URL]: https://en.wikipedia.org/wiki/Uniform_Resource_Locator
[TamperData]: https://addons.mozilla.org/en-US/firefox/addon/tamper-data/
[Firefox]: https://www.mozilla.org/en-US/firefox/new/?product=firefox-3.6.8&os=osx%E2%8C%A9=en-US
[Caesar Cipher]: https://en.wikipedia.org/wiki/Caesar_cipher
[Google Reverse Image Search]: https://www.google.com/imghp
[PicoCTF]: https://picoctf.com/
[JavaScript]: https://www.javascript.com/
[base64]: https://en.wikipedia.org/wiki/Base64
[client-side]: https://en.wikipedia.org/wiki/Client-side_scripting
[client side]: https://en.wikipedia.org/wiki/Client-side_scripting
[javascript:alert]: http://www.w3schools.com/js/js_popup.asp
[Java]: https://www.java.com/en/
[2147483647]: https://en.wikipedia.org/wiki/2147483647_%28number%29
[XOR]: https://en.wikipedia.org/wiki/Exclusive_or
[XOR cipher]: https://en.wikipedia.org/wiki/XOR_cipher
[quipqiup.com]: http://www.quipqiup.com/
[PDF]: https://en.wikipedia.org/wiki/Portable_Document_Format
[pdfimages]: http://linux.die.net/man/1/pdfimages
[ampersand]: https://en.wikipedia.org/wiki/Ampersand
[URL encoding]: https://en.wikipedia.org/wiki/Percent-encoding
[Percent encoding]: https://en.wikipedia.org/wiki/Percent-encoding
[URL-encoding]: https://en.wikipedia.org/wiki/Percent-encoding
[Percent-encoding]: https://en.wikipedia.org/wiki/Percent-encoding
[endianness]: https://en.wikipedia.org/wiki/Endianness
[ASCII]: https://en.wikipedia.org/wiki/ASCII
[struct]: https://docs.python.org/2/library/struct.html
[pcap]: https://en.wikipedia.org/wiki/Pcap
[packet capture]: https://en.wikipedia.org/wiki/Packet_analyzer
[HTTP]: https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol
[Wireshark filters]: https://wiki.wireshark.org/DisplayFilters
[SSL]: https://en.wikipedia.org/wiki/Transport_Layer_Security
[Assembly]: https://en.wikipedia.org/wiki/Assembly_language
[Assembly Syntax]: https://en.wikipedia.org/wiki/X86_assembly_language#Syntax
[Intel Syntax]: https://en.wikipedia.org/wiki/X86_assembly_language
[Intel or AT&T]: http://www.imada.sdu.dk/Courses/DM18/Litteratur/IntelnATT.htm
[AT&T syntax]: https://en.wikibooks.org/wiki/X86_Assembly/GAS_Syntax
[GET request]: https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Request_methods
[GET requests]: https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Request_methods
[IP Address]: https://en.wikipedia.org/wiki/IP_address
[IP Addresses]: https://en.wikipedia.org/wiki/IP_address
[MAC Address]: https://en.wikipedia.org/wiki/MAC_address
[session]: https://en.wikipedia.org/wiki/Session_%28computer_science%29
[Cookie Manager+]: https://addons.mozilla.org/en-US/firefox/addon/cookies-manager-plus/
[hexedit]: http://linux.die.net/man/1/hexedit
[Google]: http://google.com/
[Scapy]: http://www.secdev.org/projects/scapy/
[ARP]: https://en.wikipedia.org/wiki/Address_Resolution_Protocol
[UDP]: https://en.wikipedia.org/wiki/User_Datagram_Protocol
[SQL injection]: https://en.wikipedia.org/wiki/SQL_injection
[sqlmap]: http://sqlmap.org/
[sqlite]: https://www.sqlite.org/
[MD5]: https://en.wikipedia.org/wiki/MD5
[OpenSSL]: https://www.openssl.org/
[Burpsuite]:https://portswigger.net/burp/
[Burpsuite.jar]:https://portswigger.net/burp/
[Burp]:https://portswigger.net/burp/
[NULL character]: https://en.wikipedia.org/wiki/Null_character
[Format String Vulnerability]: http://www.cis.syr.edu/~wedu/Teaching/cis643/LectureNotes_New/Format_String.pdf
[printf]: http://pubs.opengroup.org/onlinepubs/009695399/functions/fprintf.html
[argument]: https://en.wikipedia.org/wiki/Parameter_%28computer_programming%29
[arguments]: https://en.wikipedia.org/wiki/Parameter_%28computer_programming%29
[parameter]: https://en.wikipedia.org/wiki/Parameter_%28computer_programming%29
[parameters]: https://en.wikipedia.org/wiki/Parameter_%28computer_programming%29
[Vortex]: http://overthewire.org/wargames/vortex/
[socket]: https://docs.python.org/2/library/socket.html
[file descriptor]: https://en.wikipedia.org/wiki/File_descriptor
[file descriptors]: https://en.wikipedia.org/wiki/File_descriptor
[Forth]: https://en.wikipedia.org/wiki/Forth_%28programming_language%29
[github]: https://github.com/
[buffer overflow]: https://en.wikipedia.org/wiki/Buffer_overflow
[try harder]: https://www.offensive-security.com/when-things-get-tough/
[segmentation fault]: https://en.wikipedia.org/wiki/Segmentation_fault
[seg fault]: https://en.wikipedia.org/wiki/Segmentation_fault
[segfault]: https://en.wikipedia.org/wiki/Segmentation_fault
[shellcode]: https://en.wikipedia.org/wiki/Shellcode
[sploit-tools]: https://github.com/SaltwaterC/sploit-tools
[Kali]: https://www.kali.org/
[Kali Linux]: https://www.kali.org/
[gdb]: https://www.gnu.org/software/gdb/
[gdb tutorial]: http://www.unknownroad.com/rtfm/gdbtut/gdbtoc.html
[payload]: https://en.wikipedia.org/wiki/Payload_%28computing%29
[peda]: https://github.com/longld/peda
[git]: https://git-scm.com/
[home directory]: https://en.wikipedia.org/wiki/Home_directory
[NOP slide]:https://en.wikipedia.org/wiki/NOP_slide
[NOP]: https://en.wikipedia.org/wiki/NOP
[examine]: https://sourceware.org/gdb/onlinedocs/gdb/Memory.html
[stack pointer]: http://stackoverflow.com/questions/1395591/what-is-exactly-the-base-pointer-and-stack-pointer-to-what-do-they-point
[little endian]: https://en.wikipedia.org/wiki/Endianness
[big endian]: https://en.wikipedia.org/wiki/Endianness
[endianness]: https://en.wikipedia.org/wiki/Endianness
[pack]: https://docs.python.org/2/library/struct.html#struct.pack
[ash]:https://en.wikipedia.org/wiki/Almquist_shell
[dash]: https://en.wikipedia.org/wiki/Almquist_shell
[shell]: https://en.wikipedia.org/wiki/Shell_%28computing%29
[pwntools]: https://github.com/Gallopsled/pwntools
[colorama]: https://pypi.python.org/pypi/colorama
[objdump]: https://en.wikipedia.org/wiki/Objdump
[UPX]: http://upx.sourceforge.net/
[64-bit]: https://en.wikipedia.org/wiki/64-bit_computing
[breakpoint]: https://en.wikipedia.org/wiki/Breakpoint
[stack frame]: http://www.cs.umd.edu/class/sum2003/cmsc311/Notes/Mips/stack.html
[format string]: http://codearcana.com/posts/2013/05/02/introduction-to-format-string-exploits.html
[format specifiers]: http://web.eecs.umich.edu/~bartlett/printf.html
[format specifier]: http://web.eecs.umich.edu/~bartlett/printf.html
[variable expansion]: https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html
[base pointer]: http://stackoverflow.com/questions/1395591/what-is-exactly-the-base-pointer-and-stack-pointer-to-what-do-they-point
[dmesg]: https://en.wikipedia.org/wiki/Dmesg
[Android]: https://www.android.com/
[.apk]:https://en.wikipedia.org/wiki/Android_application_package
[decompiler]: https://en.wikipedia.org/wiki/Decompiler
[decompile Java code]: http://www.javadecompilers.com/
[jadx]: https://github.com/skylot/jadx
[.img]: https://en.wikipedia.org/wiki/IMG_%28file_format%29
[binwalk]: http://binwalk.org/
[JPEG]: https://en.wikipedia.org/wiki/JPEG
[JPG]: https://en.wikipedia.org/wiki/JPEG
[disk image]: https://en.wikipedia.org/wiki/Disk_image
[foremost]: http://foremost.sourceforge.net/
[eog]: https://wiki.gnome.org/Apps/EyeOfGnome
[function pointer]: https://en.wikipedia.org/wiki/Function_pointer
[machine code]: https://en.wikipedia.org/wiki/Machine_code
[compiled language]: https://en.wikipedia.org/wiki/Compiled_language
[compiler]: https://en.wikipedia.org/wiki/Compiler
[scripting language]: https://en.wikipedia.org/wiki/Scripting_language
[scripts]: https://en.wikipedia.org/wiki/Scripting_language
[script]: https://en.wikipedia.org/wiki/Scripting_language
[shell-storm.org]: http://shell-storm.org/
[shell-storm]:http://shell-storm.org/
[shellcode database]: http://shell-storm.org/shellcode/
[gdb-peda]: https://github.com/longld/peda
[x86]: https://en.wikipedia.org/wiki/X86
[Intel x86]: https://en.wikipedia.org/wiki/X86
[sh]: https://en.wikipedia.org/wiki/Bourne_shell
[/bin/sh]: https://en.wikipedia.org/wiki/Bourne_shell
[SANS]: https://www.sans.org/
[Holiday Hack Challenge]: https://holidayhackchallenge.com/
[USCGA]: http://uscga.edu/
[United States Coast Guard Academy]: http://uscga.edu/
[US Coast Guard Academy]: http://uscga.edu/
[Academy]: http://uscga.edu/
[Coast Guard Academy]: http://uscga.edu/
[Hackfest]: https://www.sans.org/event/pen-test-hackfest-2015
[SSID]: https://en.wikipedia.org/wiki/Service_set_%28802.11_network%29
[DNS]: https://en.wikipedia.org/wiki/Domain_Name_System
[Python:base64]: https://docs.python.org/2/library/base64.html
[OpenWRT]: https://openwrt.org/
[node.js]: https://nodejs.org/en/
[MongoDB]: https://www.mongodb.org/
[Mongo]: https://www.mongodb.org/
[SuperGnome 01]: http://52.2.229.189/
[Shodan]: https://www.shodan.io/
[SuperGnome 02]: http://52.34.3.80/
[SuperGnome 03]: http://52.64.191.71/
[SuperGnome 04]: http://52.192.152.132/
[SuperGnome 05]: http://54.233.105.81/
[Local file inclusion]: http://hakipedia.com/index.php/Local_File_Inclusion
[LFI]: http://hakipedia.com/index.php/Local_File_Inclusion
[PNG]: http://www.libpng.org/pub/png/
[.png]: http://www.libpng.org/pub/png/
[Remote Code Execution]: https://en.wikipedia.org/wiki/Arbitrary_code_execution
[RCE]: https://en.wikipedia.org/wiki/Arbitrary_code_execution
[GNU]: https://www.gnu.org/
[regular expression]: https://en.wikipedia.org/wiki/Regular_expression
[regular expressions]: https://en.wikipedia.org/wiki/Regular_expression
[uniq]: https://en.wikipedia.org/wiki/Uniq
[sort]: https://en.wikipedia.org/wiki/Sort_%28Unix%29
[binary data]: https://en.wikipedia.org/wiki/Binary_data
[binary]: https://en.wikipedia.org/wiki/Binary
[automation is divine]: https://www.youtube.com/watch?v=36AA3JGRP9s
[repos]:https://help.ubuntu.com/community/Repositories/Ubuntu
[repo]:https://help.ubuntu.com/community/Repositories/Ubuntu
[repository]:https://help.ubuntu.com/community/Repositories/Ubuntu
[repositories]: https://help.ubuntu.com/community/Repositories/Ubuntu
[hex dump]: https://en.wikipedia.org/wiki/Hex_dump
[hexdump]: https://en.wikipedia.org/wiki/Hex_dump
[xxd]: http://linuxcommand.org/man_pages/xxd1.html
[mkdir]: https://en.wikipedia.org/wiki/Mkdir
[file]: https://en.wikipedia.org/wiki/File_%28command%29
[gzip]: http://www.gzip.org/
[file extension]: https://en.wikipedia.org/wiki/Filename_extension
[bzip]: http://www.bzip.org/
[bzip2]: http://www.bzip.org/
[tar]: https://en.wikipedia.org/wiki/Tar_%28computing%29
[tar command]: http://linuxcommand.org/man_pages/tar1.html
[private key]: https://help.ubuntu.com/community/SSH/OpenSSH/Keys
[s_client]: https://www.openssl.org/docs/manmaster/apps/s_client.html
[nmap]: https://nmap.org/
[IP address]: https://en.wikipedia.org/wiki/IP_address
[RSA]: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
[ssh private key]: https://help.ubuntu.com/community/SSH/OpenSSH/Keys
[file permissions]: https://www.linux.com/learn/understanding-linux-file-permissions
[octal file permission]: http://www.cyberciti.biz/faq/how-linux-file-permissions-work/
[octal file permissions]: http://www.cyberciti.biz/faq/how-linux-file-permissions-work/
[chmod]: https://en.wikipedia.org/wiki/Chmod
[diff]: http://man7.org/linux/man-pages/man1/diff.1.html
[.bashrc]: http://unix.stackexchange.com/questions/129143/what-is-the-purpose-of-bashrc-and-how-does-it-work
[bashrc]: http://unix.stackexchange.com/questions/129143/what-is-the-purpose-of-bashrc-and-how-does-it-work
[setuid]: https://en.wikipedia.org/wiki/Setuid
[user id]: https://en.wikipedia.org/wiki/User_identifier
[effective user id]: https://en.wikipedia.org/wiki/User_identifier#Effective_user_ID
[cron]: https://en.wikipedia.org/wiki/Cron
[file extension]: https://en.wikipedia.org/wiki/Filename_extension
[file extensions]: https://en.wikipedia.org/wiki/Filename_extension
[bash script]: https://linuxconfig.org/bash-scripting-tutorial
[bash script]: https://linuxconfig.org/bash-scripting-tutorial
[bash scripts]: https://linuxconfig.org/bash-scripting-tutorial
[shebang line]: https://en.wikipedia.org/wiki/Shebang_(Unix)
[she-bang line]: https://en.wikipedia.org/wiki/Shebang_(Unix)
[sha-bang line]: https://en.wikipedia.org/wiki/Shebang_(Unix)
[shabang line]: https://en.wikipedia.org/wiki/Shebang_(Unix)
[sha bang line]: https://en.wikipedia.org/wiki/Shebang_(Unix)
[nano]: https://en.wikipedia.org/wiki/GNU_nano
[text editor]: https://en.wikipedia.org/wiki/Text_editor
[whoami]: https://en.wikipedia.org/wiki/Whoami
[echo]: https://en.wikipedia.org/wiki/Echo_(command)
[md5sum]: http://www.tutorialspoint.com/unix_commands/md5sum.htm
[checksum]: https://en.wikipedia.org/wiki/Checksum
[hash]: https://en.wikipedia.org/wiki/Cryptographic_hash_function
[cut]: https://en.wikipedia.org/wiki/Cut_(Unix)
[daemon]: https://en.wikipedia.org/wiki/Daemon_(computing)
[temporary directory]: https://en.wikipedia.org/wiki/Temporary_folder
[temp directory]: https://en.wikipedia.org/wiki/Temporary_folder
[temp folder]: https://en.wikipedia.org/wiki/Temporary_folder
[temporary folder]: https://en.wikipedia.org/wiki/Temporary_folder
[seq]: http://www.cyberciti.biz/tips/tag/seq-command
[/etc/passwd]: https://en.wikipedia.org/wiki/Passwd#Password_file
[more]: https://en.wikipedia.org/wiki/More_(command)
[vi]: https://en.wikipedia.org/wiki/Vi
[vim]: http://www.vim.org/
[caesar cipher]: https://en.wikipedia.org/wiki/Caesar_cipher
[vignere cipher]: https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher
[substitution cipher]: https://en.wikipedia.org/wiki/Substitution_cipher
[DNA]: https://en.wikipedia.org/wiki/Nucleic_acid_sequence
[Python bytecode]: http://security.coverity.com/blog/2014/Nov/understanding-python-bytecode.html
[uncompyle]: https://github.com/gstarnberger/uncompyle
[Easy Python Decompiler]: https://github.com/aliansi/Easy-Python-Decompiler-v1.3.2
[marshal]: https://docs.python.org/2/library/marshal.html
[IDLE]: https://en.wikipedia.org/wiki/IDLE
[bytecode]: http://whatis.techtarget.com/definition/bytecode
[dis]: https://docs.python.org/2/library/dis.html
[rot13]: https://en.wikipedia.org/wiki/ROT13
[calendar]: https://docs.python.org/2/library/calendar.html
[datetime]: https://docs.python.org/2/library/datetime.html
[primefac]: https://pypi.python.org/pypi/primefac
[re]: https://docs.python.org/2/library/re.html
[IDA pro]: https://www.hex-rays.com/products/ida/
[IDA]: https://www.hex-rays.com/products/ida/
[QR Code]: https://en.wikipedia.org/wiki/QR_code
[RGB]: https://en.wikipedia.org/wiki/RGB_color_model
[RGB color]: https://en.wikipedia.org/wiki/RGB_color_model
[exiftool]: http://www.sno.phy.queensu.ca/~phil/exiftool/
[robots.txt]: http://www.robotstxt.org/
[XSS]: https://en.wikipedia.org/wiki/Cross-site_scripting
[cross-site scripting]: https://en.wikipedia.org/wiki/Cross-site_scripting
[cross site scripting]: https://en.wikipedia.org/wiki/Cross-site_scripting
[cookie catcher]: http://hackwithstyle.blogspot.com/2011/11/what-is-cookie-catcher-and-how-to-get.html
[johnhammond.org]: http://johnhammond.org
[HTTP cookie]: https://en.wikipedia.org/wiki/HTTP_cookie
[HTTP cookies]: https://en.wikipedia.org/wiki/HTTP_cookie
[cookie]: https://en.wikipedia.org/wiki/HTTP_cookie
[cookies]: https://en.wikipedia.org/wiki/HTTP_cookie
[HTTP GET]: http://www.w3schools.com/Tags/ref_httpmethods.asp
[tee]: https://en.wikipedia.org/wiki/Tee_(command)
[reverse engineering]: https://en.wikipedia.org/wiki/Reverse_engineering
[cryptography]: https://en.wikipedia.org/wiki/Cryptography
[crypto]: https://en.wikipedia.org/wiki/Cryptography
[sed]: https://en.wikipedia.org/wiki/Sed
[padding]: https://en.wikipedia.org/wiki/Padding_(cryptography)
[xortool]: https://github.com/hellman/xortool
[XOR Cracker]: https://wiremask.eu/tools/xor-cracker/
