Skip to content

jdubp/cyber-chef-recipes

 
 

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

66 Commits
 
 
 
 
 
 

Repository files navigation

CyberChef Recipes

A list of CyberChef recipes

For background see Twitter #cyberchef or https://bitofhex.com/2018/05/29/cyberchef/

Full credit to @GCHQ for producing the tool. See: https://gchq.github.io/CyberChef/

Recipe 1: Extract base64, raw inflate & beautify

Recipe 2: Invoke Obfuscation

Recipe 3: From CharCode

Recipe 4: Group Policy Preference Password Decryption

Recipe 5: Using Loops and Labels

Recipe 6: Google ei Timestamps

Recipe 7: Multi-stage COM scriplet to x86 assembly

Recipe 8: - Extract hexadecimal, convert to hexdump for embedded PE file

Recipe 9 - Reverse strings, character substitution, from base64

Recipe 10 - Extract object from Squid proxy cache

Recipe 11 - Extract GPS Coordinates to Google Maps URLs

Recipe 12 - Big Number Processing

Recipe 13 - Parsing DNS PTR records with Registers

Recipe 14 - Decoding POSHC2 executables

Recipe 15 - Parsing $MFT $SI Timestamps

Recipe 16 - Decoding PHP gzinflate and base64 webshells

Recipe 17 - Extracting shellcode from a Powershell Meterpreter Reverse TCP Script

Recipe 18 - Recycle Bin Parser with Subsections and Merges

Recipe 1 - Extract base64, raw inflate and code beautify

A very common scenario: extract Base64, inflate, beautify the code. You may need to then do further processing or dynamic analysis depending on the next stage.

Filename: ahack.bat

Zipped File: cc9c6c38840af8573b8175f34e5c54078c1f3fb7c686a6dc49264a0812d56b54_183SnuOIVa.bin.gz

Sample: SHA256 cc9c6c38840af8573b8175f34e5c54078c1f3fb7c686a6dc49264a0812d56b54

https://www.hybrid-analysis.com/sample/cc9c6c38840af8573b8175f34e5c54078c1f3fb7c686a6dc49264a0812d56b54?environmentId=120

Recipe Details

[{"op":"Regular expression","args":["User defined","[a-zA-Z0-9+/=]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Raw Inflate","args":[0,0,"Adaptive",false,false]},{"op":"Generic Code Beautify","args":[]}]

Recipe_1

Recipe 2 - Invoke-Obfuscation

CyberChef won't be able to handle all types of Invoke-Obfuscation, but here is one that can be decoded.

Filename: Acknowledgement NUT-95-52619.eml

Zipped File: 1240695523bbfe3ed450b64b80ed018bd890bfa81259118ca2ac534c2895c835.bin.gz

Sample: SHA256 1240695523bbfe3ed450b64b80ed018bd890bfa81259118ca2ac534c2895c835

https://www.hybrid-analysis.com/sample/1240695523bbfe3ed450b64b80ed018bd890bfa81259118ca2ac534c2895c835?environmentId=120

Recipe Details

[{"op":"Find / Replace","args":[{"option":"Regex","string":"\\^|\\\\|-|_|\\/|\\s"},"",true,false,true,false]},{"op":"Reverse","args":["Character"]},{"op":"Generic Code Beautify","args":[]},{"op":"Find / Replace","args":[{"option":"Simple string","string":"http:"},"http://",true,false,true,false]},{"op":"Extract URLs","args":[false]},{"op":"Defang URL","args":[true,true,true,"Valid domains and full URLs"]}]

Recipe_2

Recipe 3 - From CharCode

Malware and scripts often use Charcode to represent characters in order to evade from AV and EDR solutions. CyberChef eats this up.

Filename: 3431818-f71f60d10b1cbe034dc1be242c6efa5b9812f3c6.zip

Source: https://gist.github.com/jonmarkgo/3431818

Recipe Details

[{"op":"Regular expression","args":["User defined","([0-9]{2,3}(,\\s|))+",true,true,false,false,false,false,"List matches"]},{"op":"From Charcode","args":["Comma",10]},{"op":"Regular expression","args":["User defined","([0-9]{2,3}(,\\s|))+",true,true,false,false,false,false,"List matches"]},{"op":"From Charcode","args":["Space",10]}]

Recipe_3

Recipe 4 - Group Policy Preference passwords

When a new GPP is created, there’s an associated XML file created in SYSVOL with the relevant configuration data and if there is a password provided, it is AES-256 bit encrypted. Microsoft published the AES Key, which can be used to decrypt passwords store in: \\SYSVOL<DOMAIN>\Policies\

Credit: @cyb3rops

Source 1: https://twitter.com/cyb3rops/status/1036642978167758848

Source 2: https://adsecurity.org/?p=2288

Recipe Details

[{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"To Hex","args":["None"]},{"op":"AES Decrypt","args":[{"option":"Hex","string":"4e9906e8fcb66cc9faf49310620ffee8f496e806cc057990209b09a433b66c1b"},{"option":"Hex","string":""},"CBC","Hex","Raw",{"option":"Hex","string":""}]},{"op":"Decode text","args":["UTF16LE (1200)"]}]

Recipe_4

Recipe 5 - Using loops & labels

CyberChef can use labels to identify parts of the recipe and then loop back to perform operations multiple times. In this examples, there are 29 rounds of Base64 encoding which are extracted and decoded.

Credit: @pmelson

Source File: hmCPDnHs.txt

Source 1: https://pastebin.com/hmCPDnHs

Source 2: https://twitter.com/pmelson/status/1078776229996752896

Also see more example of loops over Base64: https://twitter.com/QW5kcmV3/status/1079095274776289280 (Credit: @QW5kcmV3)

Recipe Details

[{"op":"Label","args":["top"]},{"op":"Regular expression","args":["User defined","[a-zA-Z0-9+/=]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Raw Inflate","args":[0,0,"Adaptive",false,false]},{"op":"Jump","args":["top",28]},{"op":"Generic Code Beautify","args":[]}]

Recipe_5

Recipe 6 - Google ei timestamp

Google uses its own timestamp, I call ei time, which it embeds in the URL.

Source: https://bitofhex.com/2018/05/29/cyberchef/

Recipe Details

[{"op":"From Base64","args":["A-Za-z0-9-_=",true]},{"op":"To Hex","args":["None"]},{"op":"Take bytes","args":[0,8,false]},{"op":"Swap endianness","args":["Hex",4,true]},{"op":"From Base","args":[16]},{"op":"From UNIX Timestamp","args":["Seconds (s)"]}]

Recipe_6

Recipe 7 - COM scriplet to disassembled x86 assembly

This is an eleven stage decoded COM scriplet that uses Base64, Gunzip, RegEx, and Disassemble x86 instructions.

Credit: @JohnLaTwC

Filename: 41a6e22ec6e60af43269f4eb1eb758c91cf746e0772cecd4a69bb5f6faac3578.txt

Source 1: https://gist.githubusercontent.com/JohnLaTwC/aae3b64006956e8cb7e0127452b5778f/raw/f1b23c84c654b1ea60f0e57a860c74385915c9e2/43cbbbf93121f3644ba26a273ebdb54d8827b25eb9c754d3631be395f06d8cff

Source 2: https://twitter.com/JohnLaTwC/status/1062419803304976385

Recipe Details

[{"op":"Regular expression","args":["","[A-Za-z0-9=/]{40,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Remove null bytes","args":[]},{"op":"Regular expression","args":["User defined","[A-Za-z0-9+/=]{40,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Gunzip","args":[]},{"op":"Regular expression","args":["User defined","[A-Za-z0-9+/=]{40,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"To Hex","args":["Space"]},{"op":"Remove whitespace","args":[true,true,true,true,true,false]},{"op":"Disassemble x86","args":["32","Full x86 architecture",16,0,true,true]}]

Recipe_7

Recipe 8 - Extract hexadecimal, convert to hexdump for embedded PE file

This file has an embedded PE file (SHA 256: 26fac1d4ea12cdceac0d64ab9694d0582104b3c84d7940a4796c1df797d0fdc2, R5Sez8PH.exe, VT: 54/70). Using CyberChef, we can regex hexadecimal and the convert to a more easily viewable hexdump.

Source 1: https://pastebin.com/R5Sez8PH

Source 2: https://twitter.com/ScumBots/status/1081949877272276992

Recipe Details

[{"op":"Regular expression","args":["User defined","[a-fA-F0-9]{200,}",true,true,false,false,false,false,"List matches"]},{"op":"From Hex","args":["Auto"]},{"op":"To Hexdump","args":[16,false,false]}]

Recipe_8

Recipe 9 - Reverse strings, character substitution, from base64

A blob of base64 with some minor bytes to be substituted. Original decoding done by @pmelson in Python and converted to CyberChef.

Credit: @pmelson

Source 1: https://pastebin.com/RtjrweYF

Source 2: https://twitter.com/pmelson/status/1076893022758100998

Recipe Details

[{"op":"Reverse","args":["Character"]},{"op":"Find / Replace","args":[{"option":"Regex","string":"%"},"A",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"×"},"T",true,false,false,false]},{"op":"Find / Replace","args":[{"option":"Simple string","string":"÷"},"V",true,false,false,false]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"To Hexdump","args":[16,false,false]}]

Recipe_9

Recipe 10 - Extract object from Squid proxy cache

Don't manually carve out your Squid cache objects. Simply upload the file to CyberChef. This recipe will search for the magic bytes 0x0D0A0D0A, extract everything after. It then gzip decompresses the object for download.

Source: 00000915 (output should be TrueCrypt_Setup_7.1a.exe with SHA256 e95eca399dfe95500c4de569efc4cc77b75e2b66a864d467df37733ec06a0ff2)

Recipe Details

[{"op":"To Hex","args":["None"]},{"op":"Regular expression","args":["User defined","(?<=0D0A0D0A).*$",true,false,false,false,false,false,"List matches"]},{"op":"From Hex","args":["Auto"]},{"op":"Gunzip","args":[]}]

Recipe_10

Recipe 11 - Extract GPS Coordinates to Google Maps URLs

If you need to quickly triage where a photo was taken and you're lucky enought to have embedded GPS latitude and longitudes then use this recipe to quickly make a usable Google Maps URL to identify the location.

Recipe Details

[{"op":"Extract EXIF","args":[]},{"op":"Regular expression","args":["User defined","((?<=GPSLatitude:).*$)|((?<=GPSLongitude: ).*$)",true,true,false,false,false,false,"List matches"]},{"op":"Find / Replace","args":[{"option":"Extended (\\n, \\t, \\x...)","string":"\\n"},",",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Simple string","string":" "},"https://maps.google.com/?q=",true,false,true,false]}]

Recipe_11

Recipe 12 - Big Number Processing

CyberChef can handle massive numbers. Here we can use a simple recipe to change a 38-digit X509SerialNumber to its hexadecimal equivalent X.509 certificate serial number. Then we can regex the hexadecimal and insert a colon to transform it to the correct format.

Credit: @QW5kcmV3

Source: https://twitter.com/QW5kcmV3/status/949437437473968128

Recipe Details

[{"op":"To Base","args":[16]},{"op":"Regular expression","args":["User defined","[a-f0-9]{2,2}",true,true,false,false,false,false,"List matches"]},{"op":"Find / Replace","args":[{"option":"Extended (\\n, \\t, \\x...)","string":"\\n"},":",true,false,true,false]}]

Recipe_12

Recipe 13 - Parsing DNS PTR records with Registers

IP addresses in DNS PTR records are stored as least significant octet first. For example: 167.139.44.10.in-addr.arpa would relate to IP address of 10.44.139.167. Using CyberChef's registers we can allocate each octet to a memory register (or variable if it's easier to think of it that way). These can then be reversed to re-order the IP address. A find/replace tidies up the rest of the record. This could be reversed it you wanted to translate 'regular' IP addresses to search in DNS PTR records.

Recipe_13

Recipe Details

[{"op":"Fork","args":["\\n","\\n",false]},{"op":"Register","args":["(\\d{1,3}).(\\d{1,3}).(\\d{1,3}).(\\d{1,3})",true,false,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"$R0.$R1.$R2.$R3"},"$R3.$R2.$R1.$R0",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":".in-addr.arpa"},"",true,false,true,false]}]

Recipe 14 - Decoding POSHC2 executables

PoshC2 is a proxy aware C2 framework that utilises Powershell to aid penetration testers with red teaming, post-exploitation and lateral movement. The dropper is based on PowerShell and consists of a PowerShell script which is double Base64 encoded and compressed. Extracting the strings can be done with CyberChef as detailed below. Depending on the settings and customisation of the executable you may need to adjust your recipe.

Credit: @a_tweeter_user

Source: https://twitter.com/a_tweeter_user/status/1100751236687642624

Source: posh.zip (password: 'infected'. NB: this is different to the tweeted executable by @a_tweeter_user as I don't have a VT account)

Recipe_14

Recipe Details

[{"op":"Strings","args":["All",4,"Alphanumeric + punctuation (A)",false]},{"op":"Remove null bytes","args":[]},{"op":"Regular expression","args":["User defined","[a-zA-Z0-9+=]{200,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Remove null bytes","args":[]},{"op":"Regular expression","args":["User defined","[a-z0-9/\\\\+=]{100,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Raw Inflate","args":[0,0,"Adaptive",false,false]}]

Recipe 15 - Parsing $MFT $SI Timestamps

CyberChef can do just about anything with data. Here are raw hex bytes from a $MFT entry. By selecting certain bytes, and using various functions of CyberChef I can parse any part of the data as needed. This recipe will extract and parse the $SI timestamps. Encase no more!

Recipe 15

Recipe Details

[{"op":"Take bytes","args":[160,64,false]},{"op":"Regular expression","args":["User defined",".{16}",true,true,true,false,false,false,"List matches with capture groups"]},{"op":"Fork","args":["\\n","\\n",false]},{"op":"Swap endianness","args":["Hex",10,true]},{"op":"Remove whitespace","args":[true,true,true,true,true,false]},{"op":"Windows Filetime to UNIX Timestamp","args":["Nanoseconds (ns)","Hex"]},{"op":"From UNIX Timestamp","args":["Nanoseconds (ns)"]},{"op":"Merge","args":[]},{"op":"Register","args":["(.*)\\n(.*)\\n(.*)\\n(.*)",true,false,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"$R0"},"$SI Creation Time: $R0",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"$R1"},"$SI Modified Time: $R1",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"$R2"},"$SI MFT Change Time: $R2",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"$R3"},"$SI Access Time: $R3",false,false,true,false]}]

Recipe 16 - Decoding PHP gzinflate and base64 webshells

Webshells come in all shapes and sizes. For PHP webshells the combination of gzinflate and base64 can be used to obfuscate the eval data. In this example, there are 21 rounds of compression and base64 that we can quickly parse out using labels and loops.

Source: https://github.com/LordWolfer/webshells/blob/b7eefaff64049e3ff61e90c850686135c0ba74c4/from_the_wild1.php

Recipe 16

Recipe Details

[{"op":"Label","args":["start"]},{"op":"Regular expression","args":["User defined","[a-zA-Z0-9=/+]{10,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Raw Inflate","args":[0,0,"Block",false,false]},{"op":"Jump","args":["start",21]}]

Recipe 17 - Extracting shellcode from a Powershell Meterpreter Reverse TCP script

Often seen in @pmelson's Pastbin bot @scumbots, this peels away multiple layers of an encoded Powershell script to display the shellcode. From here you could extract PUSH statements to try and identify the IP address & port, but you'll get too many false positives. So you're better off using a tool like scdbg (see: http://sandsprite.com/blogs/index.php?uid=7&pid=152)

Source: https://twitter.com/ScumBots/status/1121854255898472453

Source: https://pastebin.com/9DnD6t6W

Recipe 17

Recipe Details

[{"op":"Regular expression","args":["User defined","[a-zA-Z0-9=/+]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Remove null bytes","args":[]},{"op":"Regular expression","args":["User defined","[a-zA-Z0-9=/+]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Gunzip","args":[]},{"op":"Regular expression","args":["User defined","[a-zA-Z0-9=/+]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"To Hex","args":["None"]},{"op":"Disassemble x86","args":["32","Full x86 architecture",16,0,true,true]}]

Recipe 18 - Recycle Bin Parser with Subsections and Merges

Subsections and Merges are powerful tools in CyberChef that allow the application of ingredients to a selection of data rather than the whole input file. This section can then be merged together to continue on the whole input. In an awesome piece of work @GlassSec has created a Windows Recycle Bin parser using CyberChef indicating the possibilities of these functions is endless.

Source: https://gist.github.com/glassdfir/f30957b314ec39a8aa319420a29ffc76

Credit: https://twitter.com/GlassSec

Recipe 18

[{"op":"Conditional Jump","args":["^(\\x01|\\x02)",true,"Error",10]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^(\\x02.{23})(....)"},"$1",false,false,false,false]},{"op":"Subsection","args":["^.{24}(.*)",true,true,false]},{"op":"Decode text","args":["UTF16LE (1200)"]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^(.*)."},"\\nDeleted File Path: $1",false,false,false,false]},{"op":"Merge","args":[]},{"op":"Subsection","args":["^.{16}(.{8})",false,true,false]},{"op":"Swap endianness","args":["Raw",8,true]},{"op":"To Hex","args":["None"]},{"op":"Windows Filetime to UNIX Timestamp","args":["Seconds (s)","Hex"]},{"op":"From UNIX Timestamp","args":["Seconds (s)"]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^(.* UTC)"},"\\nFile Deletion Time: $1",true,false,true,false]},{"op":"Merge","args":[]},{"op":"Subsection","args":["^.{8}(.{8})",true,true,false]},{"op":"To Hex","args":["None"]},{"op":"Swap endianness","args":["Hex",8,true]},{"op":"From Base","args":[16]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^(.*)"},"\\nDeleted File Size: $1 bytes",true,false,true,true]},{"op":"Merge","args":[]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^.{8}"},"******** WINDOWS RECYCLE BIN METADATA ********",true,false,false,false]},{"op":"Jump","args":["Do Nothing",10]},{"op":"Label","args":["Error"]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^.*$"},"This doesn't look like a Recycle Bin file to me ",true,false,true,false]},{"op":"Label","args":["Do Nothing"]}]

Notes

Happy to add (and learn) more. Pull request or tweet to @mattnotmax!

Please include original source of text and recipe developer (if not yourself). For consistency in pasting into CyberChef I have found the best results are to export the function as compact JSON.

About

A list of cyber-chef recipes

Resources

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published