Adding Bytes Using a Hex Editor

Question

Due to incompatibility of root account and sandbox, I need to manually disable sandboxing of MS Office applications (so that it can be activated) by changing the value of com.apple.security.app-sandbox within the application binary (/Applications/Microsoft Word.app/Contents/MacOS/Microsoft Word) from <true/> to <false/>.

However, this change would lead the addition of a byte, and I can't find any documentation on how to insert a byte. I'm using hexedit, installed with brew (brew install hexedit).

Also, if someone can provide a script to automatically detect and edit that flag, that will be great. Here is an excerpt:

Answer 1

You don't need additional software for this, the standard vi installed by macOS can edit binary files.

cd /Applications/Microsoft\ Word.app/Contents/MacOS/
cp Microsoft\ Word Microsoft\ Word.orig
vi -b Microsoft\ Word

Now, assuming you are not used to vi:

• Type /app-sandbox followed by Return to jump to the definition you want to change

• Press Return again to move the cursor to the next line
• Type ct/<false followed by ESC

• Type ZZ to save and quit

PS: If you get stuck within vi, press ESC twice and then type :q! to quit without saving.

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If you want to script this, use (at our own risk)

vi -b Microsoft\ Word '+/app-sandbox/+1s/true/false/' '+wq'

which basically does the same thing as the interactive sequence above in one go.

• /app-sandbox/+1 makes the following command (the substitution) only apply on the line after the one containing the app-sandbox string
• s/true/false/ is the substitution and replaces true by false
• wq writes the modified file back to disk and quits