HelloKittify
The Long Troll
Everyone knows the old office trick of changing your buddy's desktop to something embarrassing (like Hello Kitty if it's a guy) if he leaves his workstation unlocked. Well, This is a variant on that that instead changes his lockscreen background. This way, the troll goes undetected for much longer and hilarity is prolonged. Enjoy!
Also includes an undo script.
Feel free to change out the assets as desired, but be sure to look up what resolutions are supported, there are some strange restrictions (off the top of my head, must be a jpg, no larger than 245k and only certain resolutions need apply).
Usage:
Run hk.bat to copy the payload over. The .reg file activates the OEM background option (if it's not activae already) Payload extensions are obfuscated only so that they are not obviously images (helps you not to get caught) Similarly run undo.bat to restore the default background (useful for testing)
Limitations:
This only works on Windows 7 You must have enough access that you can modify the registry OR the system must already be configured to allow OEM wallpapers
Supported resolutions for lockscreen images:
768×1280
960×1280
900×1440
1024×768 < -- included assets are all this size
1024×1280
1280×768
1280×960
1280×1024
1360×768
1440×900
1600×1200
1920×1200
Information for this troll was gathered from this helpful post: http://helpdeskgeek.com/windows-7/change-the-windows-7-login-screen-background-image/