Didier Stevens

Sunday 28 February 2016

Update: translate.py Version 2.2.0 for Locky JavaScript Deobfuscation

Filed under: maldoc,Malware,My Software,Update — Didier Stevens @ 10:45

Over at the ISC Diary I have an entry on Locky JavaScript Deobfuscation. I use my translate tool to perform part of the static analysis.

When you read this diary entry, you’ll see that I have to create 2 Python scripts to be used by translate.py to search with a regular expression and replace all matches with the output of a Python function.

I updated translate.py so that I don’t have to create Python scripts for this regex search-and-replace, but that I can do it from the command-line with a new option. This new option (-r, –regex) takes a regular expression and does a search-and-replace.

Here are the 2 “scripts” using this new option:

translate.py -r "\([^\\\(]+\\u([0-9a-f]{4})[a-z]+'\.e\(\)\)" "lambda oMatch: chr(39) + chr(int(oMatch.group(1), 16)) + chr(39)"
translate.py -r "('[^']*' ?\+ ?)+'[^']*'" "lambda oMatch: chr(39) + eval(oMatch.group(0)) + chr(39)"

If you just want to do a search-and-replace, you can use a constant regex and lambda function, like this (replace False with True):

translate.py -r "False" "lambda oMatch: 'True'"

translate_v2_2_0.zip (https)
MD5: D561D9987A3E5264E40A4B5C4057A732
SHA256: BC532BD5C7DD86DCADDF7B7B9A34453E983E226E103E0591E7D480BB43C350E0


  1. Hi,
    Thank you for this post. I’m not able to find translate.py v2.2 on your website, can you say me where it can be downloaded ?


    Comment by Nicolas — Tuesday 1 March 2016 @ 15:32

  2. Hi Nicolas,

    I made a mistake, I forgot to include a download link on this blog post.
    But you can also find it on its dedicated page: https://blog.didierstevens.com/programs/translate/

    Comment by Didier Stevens — Tuesday 1 March 2016 @ 15:43

  3. Thanks !

    Comment by Nicolas — Tuesday 1 March 2016 @ 15:53

  4. […] Update: translate.py Version 2.2.0 for Locky JavaScript Deobfuscation […]

    Pingback by Overview of Content Published In February | Didier Stevens — Tuesday 29 March 2016 @ 0:01

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