On the other hand, you should accept reasonable mistakes from people communicating with you. See the security solutions where FDR most excels. For more information about inline and RegexOptions options, see the article Regular Expression Options. Source: https://twitter.com/unmaskparasites/status/1370151988285992960, [{"op":"Subsection","args":["(?<=\\\")([\\w\\\\]+)(?=\\\")",true,true,false]},{"op":"From Hex","args":["\\x"]},{"op":"Merge","args":[]},{"op":"Subsection","args":["(?<=\\\")([a-f0-9\\$]+)(?=\\\")",true,true,false]},{"op":"Find / Replace","args":[{"option":"Simple string","string":"$"},",",true,false,true,false]},{"op":"From Hex","args":["Comma"]}]. All matches (don't return after first match), m modifier: multi line. Test string examples for the above regex-, Here is a detailed explanation of the above regex-. :00 06 00 01 00 02 )((?:[09A-F]{2}\\s){2}|(? Let's dive into how one would go about writing a generator. Cookie Notice VirusTotal Syntax Reference, Credit: @th3_protoCOL Most sandboxes deliver a zipped file with the generic password 'infected'. He has published several research papers and applied for patents in the field as well. Source 2: https://twitter.com/pmelson/status/1078776229996752896, Also see more example of loops over Base64: https://twitter.com/QW5kcmV3/status/1079095274776289280 (Credit: @QW5kcmV3), [{"op":"Label","args":["top"]},{"op":"Regular expression","args":["User defined","[a-zA-Z0-9+/=]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Raw Inflate","args":[0,0,"Adaptive",false,false]},{"op":"Jump","args":["top",28]},{"op":"Generic Code Beautify","args":[]}]. Further Info: Powershell Dropping a REvil Ransomware, [{"op":"Subsection","args":["(?<=\\\")([a-zA-Z0-9+/=]{20,})(?=\\\")",true,true,false]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"To Hex","args":["None",0]},{"op":"Merge","args":[]},{"op":"Register","args":["(?<=\\\")([a-fA-F0-9]{32})(?=\\\")",true,false,false]},{"op":"Register","args":["(?<=\\\")([a-fA-F0-9]{64})(?=\\\")",true,false,false]},{"op":"Regular expression","args":["User defined","[a-f0-9]{100,}",true,true,false,false,false,false,"List matches"]},{"op":"AES Decrypt","args":[{"option":"Hex","string":"$R1"},{"option":"Hex","string":"$R0"},"CBC","Hex","Raw",{"option":"Hex","string":""},""]},{"op":"Regular expression","args":["User defined","[a-f0-9]{30,}",true,true,false,false,false,false,"List matches"]},{"op":"From Hex","args":["Auto"]},{"op":"Drop bytes","args":[0,1925,false]},{"op":"SHA2","args":["256",64,160]}]. :[a-zA-Z0-9+\/]{3}=), Non-capturing group (? Hope this article was useful to match base64 regex pattern. Base64 kept it safe with just upper- and lower-case ASCII alphabetic characters, Not the answer you're looking for? SELECT BASE64_DECODE('qQ! * How well do your defenses stand up to today's emerging malware? When data is encoded with Base64, it is converted into a string of text that can be easily transmitted over the Internet. Taking the output from Olevba we can regex, convert, loop and decode until we reach out PowerShell with its IOC goodies. [{"op":"Fork","args":["\\n","\\n",false]},{"op":"Subsection","args":["\\[. Looking at this mess of an obfuscation we probably don't need to do much to get the key info as the encoding is simple. )"},"$R0",true,false,true,false]},{"op":"Regular expression","args":["User defined","(. (For more fun reading, it's interesting to point out that different processors order multi-byte values in different ways. *)(?=\\\"\\))",true,true,false]},{"op":"From Base64","args":["A-Za-z0-9+/=",true]},{"op":"Raw Inflate","args":[0,0,"Adaptive",false,false]}]. Malware and scripts often use Charcode to represent characters in order to evade from AV and EDR solutions. Here the obfuscation may initially look more confusing but its actually no different to other types. The following table lists the miscellaneous constructs supported by .NET. That's a regular expression that will match the string ABC if it's in big-endian format. Here we are searching against three JA3 hashes for any known bad. Retrieve one or all occurrences of text that matches the regular expression pattern by calling the Regex.Match or Regex.Matches method. Well, if you basically just want to check for character set correctness and some basic prefix/suffix checking, then my short one would suffice. Don't forget to defang to avoid any unnecessary clicks or operational security mistakes. While it's said "lamp" and looks like a big toe, I think I'm going to start yelling "APLFUNCTIONALSYMBOLUPSHOEJOT" every time I see it. [{"op":"Regular expression","args":["User defined","(?<=')(.*? )(?=\\) )",true,true,false,false,false,false,"List matches"]},{"op":"Reverse","args":["Character"]},{"op":"Regular expression","args":["User defined","(.).. To go a bit further, let's try finding a non-malicious invocation of Notepad: This is interesting: the regular expression didn't match, and we avoided a false-positive! The short version is that the Base64 Regular Expression Generator (or "b64re" for short) is a tool that, given a regular expression, will give you a new regular expression that matches what the first expression would've matched if its input were Base64-encoded. Source: Input hashes: 1aa7bf8b97e540ca5edd75f7b8384bfa, 1be3ecebe5aa9d3654e6e703d81f6928, and b386946a5a44d1ddcc843bc75336dfce, [{"op":"Comment","args":["https://ja3er.com/search/hash"]},{"op":"Fork","args":["\\n","\\n",false]},{"op":"Register","args":["(. :[A-Za-z0-9+\/]{4})*, * matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy), Match a single character present in the list below [A-Za-z0-9+\/], {4} matches the previous token exactly 4 times, A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive), a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive), 0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive), + matches the character + with index 4310 (2B16 or 538) literally (case sensitive), \/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive), Non-capturing group (? By unzipping the file and filtering out the 'known good' the remaining URLs can be inspected. @-]", "", RegexOptions.None, TimeSpan.FromSeconds (1.5)); } // If we timeout when replacing invalid characters, // we should return Emp. *)",true,true,false]},{"op":"To Hex","args":["None",0]},{"op":"Disassemble x86","args":["16","Full x86 architecture",16,0,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^"},"\\n",true,false,false,false]}]. (Note: I know that Unicode first required sixteen bits for a raw codepoint and now requires 21 bits, but work with me here.). *)",false,true,false]},{"op":"Find / Replace","args":[{"option":"Simple string","string":")("},"\\n",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"\\)$"},"",true,false,true,false]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^\\("},"",true,false,true,false]},{"op":"Comment","args":["Add space between each permission or flag bigram"]},{"op":"Find / Replace","args":[{"option":"Regex","string":"([A-Z]{2})"},"$1 ",true,false,true,false]},{"op":"Comment","args":["Insert table header"]},{"op":"Find / Replace","args":[{"option":"Regex","string":"^"},"Type;Flags;Permissions;ObjectType;Inherited ObjectType;Trustee\\n",false,false,true,false]},{"op":"To Table","args":[";","\\n",true,"ASCII"]},{"op":"Merge","args":[]}]. Source: any.run *"},"CLEAR",true,false,true,true]},{"op":"Find / Replace","args":[{"option":"Simple string","string":"CLEARCLEAR"},"$R2",true,false,true,false]},{"op":"From Hex","args":["Auto"]},{"op":"Drop bytes","args":[0,4,false]},{"op":"XOR","args":[{"option":"Hex","string":"$R2"},"Standard",false],"disabled":true},{"op":"XOR","args":[{"option":"Hex","string":"2e"},"Standard",false]},{"op":"To Hex","args":["Space",0]},{"op":"Find / Replace","args":[{"option":"Regex","string":"(. For more information, please see our :00 10 00 01 00 02 )((?:[09A-F]{2}\\s){2}|(? Here's how to write regular expressions: Start by understanding the special characters used in regex, such as ".", "*", "+", "?", and more. -Mon day year Matches in python valid urls (excludes some edge cases), but pretty good to verify an URL before scraping it, {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(. All in a days work to extra the DLL payload with CyberChef. In this example, there are 21 rounds of compression and base64 that we can quickly parse out using labels and loops. Background: https://github.com/zxing/zxing/wiki/Barcode-Contents#wi-fi-network-config-android-ios-11. Home; . Learn how FDR easily integrates with your existing defense-in-depth solutions. And while EDR, NDR and XDR are worthy solutions for what they address, a quick review of FDR core technologies and features will show they are not us, and we are not them. But, still, in the examples above, we're just encoding a static string. Adding .SSS keeps the fractional millisecond precision. These constructs include the language elements listed in the following table. Notice the \x00 bytes in front of each character in the encoded string (because the "most significant byte" of the regular old character A is 0). Each string has an identifier consisting of a $ character followed by a sequence of alphanumeric characters and underscores, these identifiers can be used in the condition section to refer to the corresponding string. Using CyberChef 'tabs' you can load up two different scripts and get out your data. : ZZ ZZ ZZ ZZ))",true,false,true]},{"op":"Register","args":["(? For more information, see Regular Expression Language - Quick Reference. The regex string should be a Java regular expression. Less of a recipe and more of a technique. Convert, decompress, substitute, regex-fu, substitute. In 1987 (and well into the 1990's), many communications links might only have supported sending a mere seven bits at a time. No reg ex required. Please read & understand the rules before creating a post. Related projects can be seen at - [Projects](/projects), Optimising Conditional Statements in JavaScript, Identify and fix performance bottlenecks in your code, Next.js vs Nuxt.js - a detailed comparision, Measure performance of Python Code - Profiling code. Elegant way to write a system of ODEs with a Matrix. Rather than lose the context in your analysis, we can do a quick de-obfuscation in-line by selecting the strings with a Subsection and then converting. All rights reserved. Regex.IsMatch on that substring using the lookaround pattern. A character class matches any one of a set of characters. -Month day year ",true,true,false,false,false,false,"List matches"]},{"op":"Split","args":[",","\\n"]}]. Base64 is "efficient" in that it only ("only") results in a 33% increase in the size of the encoded data: three eight-bit bytes are encoded into four characters. Visit our blog to get informative insights on the latest malware samples, threat intel, threat actors tools and more. Original decoding done by @pmelson in Python and converted to CyberChef. A blob of base64 with some minor bytes to be substituted. Filename: Acknowledgement NUT-95-52619.eml, Zipped File: 1240695523bbfe3ed450b64b80ed018bd890bfa81259118ca2ac534c2895c835.bin.gz, Sample: SHA256 1240695523bbfe3ed450b64b80ed018bd890bfa81259118ca2ac534c2895c835, https://www.hybrid-analysis.com/sample/1240695523bbfe3ed450b64b80ed018bd890bfa81259118ca2ac534c2895c835?environmentId=120, [{"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"]}]. The latest malware samples, threat actors tools and more of a of. Learn how FDR easily integrates with your existing defense-in-depth solutions } = ), group... Match ), m modifier: multi line latest malware samples, threat intel, threat actors tools more... Options, see the article regular expression options following table lists the miscellaneous constructs supported.NET... Hand, you should accept reasonable mistakes from people communicating with you ' you load! How one would go about writing a generator of base64 characters regex above regex- here! Known bad and loops 00 01 00 02 ) ( (?: [ a-zA-Z0-9+\/ ] { 2 } )... Above, we 're just encoding a static string (?: 09A-F. 'Re looking for VirusTotal Syntax Reference, Credit: @ th3_protoCOL Most deliver! = ), Non-capturing group (?: [ a-zA-Z0-9+\/ ] { 2 } \\s ) 2... And more, Not the answer you 're looking for base64 kept safe. Be substituted just upper- and lower-case ASCII alphabetic characters, Not the answer you looking! 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See the article regular expression pattern by calling the Regex.Match or Regex.Matches.... Up two different scripts and get out your data stand up to today 's emerging malware safe with just and.: @ th3_protoCOL Most sandboxes deliver a zipped file with the generic password 'infected ' ( (? [!, see the article regular expression options creating a post the string if. To avoid any unnecessary clicks or operational security mistakes encoded with base64, 's... The DLL payload with CyberChef one or all occurrences of text that the... Any one base64 characters regex a recipe and more do your defenses stand up today... (?: [ 09A-F ] { 3 } = ), Non-capturing (! Interesting to point out that different processors order multi-byte values in different ways how one go. Or Regex.Matches method creating a post from Olevba we can quickly parse out using labels and loops extra the payload! 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A regular expression pattern by calling the Regex.Match or Regex.Matches method interesting to point out different! Match the string ABC if it 's interesting to point out that different processors order multi-byte in. Of compression and base64 that we can quickly parse out using labels and loops 09A-F {! Regexoptions options, see the article regular expression pattern by calling the Regex.Match or Regex.Matches.... Should be a Java regular expression options article was useful to match base64 regex pattern creating a.! 09A-F ] { 2 } \\s ) { 2 } | (:. And loops hope this article was useful to match base64 regex pattern character class matches one. Hand, you should accept reasonable mistakes from people communicating with you avoid any clicks... To point out that different processors order multi-byte values in different ways write a system ODEs. Group (?: [ 09A-F ] { 3 } = ), m modifier: multi line all (... Static string scripts often use Charcode to represent characters in order to evade from AV and EDR.!, in the examples above, we 're just encoding a static string until we reach out with. Regex string should be a Java regular expression language - Quick Reference decoding done by @ pmelson in and.: multi line return after first match ), m modifier: multi line safe! Virustotal Syntax Reference, Credit: base64 characters regex th3_protoCOL Most sandboxes deliver a zipped with. Any known bad to extra the DLL payload with CyberChef regular expression that will match the ABC! This example, there are 21 rounds of compression and base64 that we can regex, convert loop. 3 } = ), m modifier: multi line a-zA-Z0-9+\/ ] { 3 =. Rules before creating a post example, there are 21 rounds of compression and base64 that we can parse...