title: What kind of attack is this: (="...?return="><noembed><img+src%3D...")
body: <p>My server is throwing errors like this. I suppose some kind of attack is takign place. I have IIS7, Windows server 2012.</p>
  
  <pre><code>System.Web.HttpRequestValidationException (0x80004005): A potentially dangerous Request.RawUrl value was detected from the client (="...?return="&gt;&lt;noembed&gt;&lt;img+src%3D...").
     at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
     at System.Web.HttpRequest.get_RawUrl()
     at System.Web.UI.Page.ValidateRawUrlIfRequired()
     at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
     at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
     at System.Web.UI.Page.ProcessRequest()
     at System.Web.UI.Page.ProcessRequest(HttpContext context)
     at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
     at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
     at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously)
  </code></pre>