I need to open an excel file and see its contents which is locked with password. As I made some research on the internet, I have found that only way was a brute force attack. So I used John the Ripper on Ubuntu, and detected and extracted hash of the password, which I believe is encrypted in RC4 format, a format used for encrypting office files usually. According to this, I have 2 questions;

  1. How to make sure what encryption algorithm does xls files use? (My hash starts with $oldoffice$0*, and I am not sure if it really is RC4, because some sources tell it is a combination of hashing algorithms such as $0/$1, MD5 + RC4, collider #1)
  2. What is the corresponding format for this type of hash in John The Ripper? (Because in order to decrypt the file, John asks me to indicate the format by for example --format=MD5)

Thank you in advance


You must log in to answer this question.

Browse other questions tagged .