Advanced PDF Password Recovery Pro is a program that helps you decrypt protected Adobe Acrobat PDF files that have user and/or owner passwords set, preventing the file from opening or editing, printing, selecting text and graphics etc.
If only owner password is set, password recovery is not needed at all, but the file is being decrypted instantly (so all restrictions are being removed).
User password can be recovered using brute-force and dictionary attacks; also, the program supports key attack that allows to decrypt PDF 1.3 (Acrobat 4.x) files regardless the password length, guaranteed - that takes only 4-5 days on modern dual-CPU systems.
Advanced PDF Password Recovery Pro doesn't work with documents which have user-level passwords (preventing the files from being opened), if both user and owner passwords are unknown; and PDF files protected with any 3rd party security plug-ins.
Professional edition also allows to search for "owner" and "user" passwords with brute-force and dictionary attacks, effectively optimized for speed (however, don't expect to recover long passwords in a resonable time with these attacks).
In addition, Advanced PDF Password Recovery Pro has Key search attack, which guarantees the decryption of PDF 1.3 files (Acrobat 4.x or older) regardless the password length, by trying all possible 40-bit encryption keys (it takes about 3-4 days on modern dual-CPU systems).
Warning: APDFPR does NOT work on Mac computers with Virtual PC; unfortunately, it seems to be a problem of Virtual PC itself. However, APDFPR seems to be working just fine on SoftWindows from FWB Software; you can also try RealPC from the same company.
Known bugs and limitations
The program can process files encrypted in mode 1 with standard encryption handler only. The documents protected with any other encryption handlers (like FileOpen, SASS_INTERNET_STDS from Standards Australia Software Services, or SoftLock's Acrobat Security Plug-Ins) cannot be decrypted.
Please also note that "key attack" is not applicable to PDF 1.4/1.5/1.6 files (Acrobat 5/6/7, respectively) with 128-bit encryption.
The program cannot (yet) work with some files created in Adobe Acrobat 6.0 and 7.0 (PDF 1.5 and 1.6 specification).
Requirements:
· about 4 megabytes of free space on hard disk (4 gigabytes for Enterprise version)
Limitations:
· Unregistered (trial) version decrypts only first 10% pages (but at least one page) of the documents, and replaces all other pages with blank (empty) ones; with a brute-force attack, passwords longer than 4 characters cannot be recovered; some dictionary-attack options are disabled.
