AAAAAAFuAAIAAAZNYWMgT1MAAAAAAAAAAAAAAAAAAAAAAAAAAADMrsHTSCsAAAALuG8NYWxleHN1Y2tzLmRpYwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAPJXS83SjIoAAAAAAAAAAP////8AAAkgAAAAAAAAAAAAAAAAAAAAB0Rlc2t0b3AAABAACAAAzK6zwwAAABEACAAAzdJ+egAAAAEADAALuG8AC7hIAADK3wACADFNYWMgT1M6VXNlcnM6AGFuZHJld3ByeWRlOgBEZXNrdG9wOgBhbGV4c3Vja3MuZGljAAAOABwADQBhAGwAZQB4AHMAdQBjAGsAcwAuAGQAaQBjAA8ADgAGAE0AYQBjACAATwBTABIAJ1VzZXJzL2FuZHJld3ByeWRlL0Rlc2t0b3AvYWxleHN1Y2tzLmRpYwAAEwABLwAAFQACABL//wAA
C'est un champ de données de la ~/Library/Preferences/com.microsoft.office.plist
pour Microsoft Office 2011 Mac.
Il décode partiellement en utilisant base64 mais ne semble pas être complètement base64.
Edit : Voici un autre exemple.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<data>AAAAAAFWAAIAAAZNYWMgT1MAAAAAAAAAAAAAAAAAAAAAAAAAAADMrsHTSCsAAAALuG8HMm5kLmRpYwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAPgev83SjIoAAAAAAAAAAP////8AAAkgAAAAAAAAAAAAAAAAAAAAB0Rlc2t0b3AAABAACAAAzK6zwwAAABEACAAAzdJ+egAAAAEADAALuG8AC7hIAADK3wACACtNYWMgT1M6VXNlcnM6AGFuZHJld3ByeWRlOgBEZXNrdG9wOgAybmQuZGljAAAOABAABwAyAG4AZAAuAGQAaQBjAA8ADgAGAE0AYQBjACAATwBTABIAIVVzZXJzL2FuZHJld3ByeWRlL0Rlc2t0b3AvMm5kLmRpYwAAEwABLwAAFQACABL//wAA</data>
</plist>