How to Crack Siemens Step7 PLC Password

How to Crack Password of FB,FC blocks in Siemens Step 7::

There is two ways:


Step 1: Find a file named SUBBLK.DBF from your project e.g.

…\PROJECT\ombstx\offline\00000001\ folder where PROJECT is the directory containing your S7 Project.

Step 2: Open SUBBLK.DBF with Microsoft Access Office Access 2007.

Step 3: Y0u will find Password coloumn in it.

Step 4: Change All 3 to 0 & save the file.

Step 5: Open your project file using step 7 s/w.

Step 6: All Password are removed.



Step 1: Download *.dbf file editor. The free DOS based dbf editor is the one I’d used. You can download it from,

Step 2: Extract dbf_edit.exe from the zipped file. Put it somewhere to easily access it. I’d put it inside a folder named dbfedit in C: drive. So path to run the editor is C:\DBFEDIT>dbfedit.exe

Step 3: To unlock the blocks, copy a file named SUBBLK.DBF from …\PROJECT\ombstx\offline\00000001\ folder where PROJECT is the directory containing your S7 Project. Paste this file inside C:\DBFEDIT\ folder.

Step 4: Open Command Prompt (DOS window) via clicking on

Start → Run → type ‘cmd’ → press enter


Start → All Programs → Accessories → Command Prompt

Step 5: Follow these commands,

C:>cd dbfedit

C:\DBFEDIT>dbfedit.exe subblk.dbf

A DOS based application will open. Search for the PASSWORD column. And change all 3 into 0 to unlock the blocks. Press Esc/F10 key to save and exit.


Step 6: Copy the SUBBLK.DBF file inside C:\DBFEDIT\ folder and paste it at it’s original location. Always remember to make the backup of original SUBBLK.DBF.

Step 7: Now open the project in SIMATEC Step 7 software. All the blocks are unlocked.

Author - Tushar