Didier Stevens

–prefix and –suffix can now also be filenames.

cut-bytes_V0_0_17.zip (http)
MD5: 86D0692C6303248639A740E7A2AC4525
SHA256: D4FCFBD2305D7E5E97AB993741DF95B4565A882B0CD7DBA061D09578A1DDADA7

This is an update for plugin plugin_biff.py.

Protected xls files (workbook protection, sheet protection) are protected with a password, but are not encrypted.

The password is hashed to a 16-bit hash called verifier, such a short hash gives ample opportunity for hash collisions.

I calculated passwords for all possible hash values (32768, or 0x8000) mostly with letters and digits, some with special characters (verifier table). This verifier table is not a rainbow table, because the table contains all possible hash values and a corresponding password.

If a verifier can not be cracked with a provided password list, the password will be taken from the verifier list.

Example: this spreadsheet has a sheet protected with password azeqsdwxc, which is not in the embedded password list (obtained from John The Ripper); thus the password from the verifier table is taken (bbbbhz):

Passwords azeqsdwxc and bbbbhz both hash to the same verifier value (0xd9b1), thus there is a hash collision, and both passwords can be used to unprotect the sheet.

This is a bugfix release for @files.

This small update for emldump adds support for UTF8 files that start with a BOM.

New option -O allows to use a function that receives a object per line as argument.

Like option -n, option -O is used to invoke a single Python function taking one argument, but this time the argument is an object in stead of a string. The object has several properties: item is the line (string), left is the previous line, right is the next line, index is equal to the line counter – 1.