Didier Stevens

This new version of oledump.py brings extra JSON support and a new indicator.

Existing option -j (–jsonoutput) produces JSON output: a JSON object with the content of each individual stream (BASE64 encoded).

This option (-j) can now be used together with option -v (–vbadecompress) to produce a JSON object with the VBA code (BASE64 encoded) of each VBA module stream.

And there is a new indicator (!) :

This indicator is used for VBA module streams for which oledump is not able to recognize “normal” VBA source code (e.g. starting with something else than attributes). Here is an example of a sample that would cause this ! indicator to appear: AV Cleaned Maldoc.

oledump_V0_0_55.zip (https)
MD5: 499B66DC3BAF86BDA4BC0370E3C18A1A
SHA256: ABEABFF0F1F5AA2239AFCDE73A676D4E8D9BA2F82C03B8663FFAB6F8D3A360E7

This is a Python 3 bug fix version.

translate_v2_5_10.zip (https)
MD5: DB9574D664257263C51FE7C74C7B281E
SHA256: E8993B3F2C25A92A9F4583636E1CEF79D79649B29FFF56EAA9AF8A30FCF9B9A6

This new version of strings.py, my tool to extract strings from arbitrary files, adds option -P to add support for Pascal strings.

A Pascal string is a string that is internally stored with a length-prefix: an integer that counts the number of characters inside the string.

The Unix strings command, and my strings.py tool, can extract Pascal strings without any problem, because they just search for a sequence of characters, without looking for a terminating NULL character (C-string) or a length-prefix (P-string ot Pascal string).

But with option -P, you can direct my tool strings.py to only extract Pascal strings, by checking if character sequences are prefixed with an integer that is equal to the number of characters inside the string. Strings that do not match that requirement are ignored.

Since an integer can be represented internally with different byte formats, you have to provide a value to option -P that indicates how the integer is stored internally. I use the same format as Python’s struct module to represent that format. For example, “<I” is a little-endian, unsigned 32-bit integer. That is how a string is represented in Delphi, as can be seen in this example of a Delphi malware sample:

The strings you see here are all found inside the sample, and are prefixed by their length. If you wouldn’t use option -P, then these strings would also be extracted, but they would not stand out amid the other strings that are not prefixed by their length.

Delphi also supports the ShortString type: one byte to encode the length. These can be found with option -P “<B”: little-endian, unsigned 8-bit integer:

strings_V0_0_5.zip (https)
MD5: A4BF314BE0A72972ECA7B14B558610E6
SHA256: 30E9E9BB618006445483AA78F804766D8FFA518974B81F9B68FF534BEA30B072

This is a small bug fix release for Python 3.

translate_v2_5_9.zip (https)
MD5: 8EC7A9F0738C86CCF2F0B44D3994E798
SHA256: 3C469996F7014CC1BD5D4F02157B7D5803698D93018360904B79EA2A1601BD10