Hi Michael, we weren't able to find any firm evidence of what happened other than both databases were trashed with missing data including entire tables.

There is someone trying to hack into the upgraded site at the moment, the event logs are full of sets of 2 failed login attempts using random, user ID's followed by an error message:

AssemblyVersion:7.3.1
PortalID:0
PortalName: XXXXXXXXXXXXXXXXXX
UserID:-1
UserName:
ActiveTabID:56
ActiveTabName:Home
RawURL:/Home.aspx?ctl=register
AbsoluteURL:/Default.aspx
AbsoluteURLReferrer:
UserAgent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36
DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke
ExceptionGUID:d9a2ae41-bf5f-4631-b13d-f3d7fcf62f5a
InnerException:Thread was being aborted.
FileName:
FileLineNumber:0
FileColumnNumber:0
Method:System.Threading.Thread.AbortInternal
StackTrace:
Message:
System.Threading.ThreadAbortException: Thread was being aborted.
at System.Threading.Thread.AbortInternal()
at System.Threading.Thread.Abort(Object stateInfo)
at System.Web.HttpResponse.AbortCurrentThread()
at System.Web.HttpResponse.End()
at System.Web.HttpResponse.Redirect(String url, Boolean endResponse, Boolean permanent)
at System.Web.HttpResponse.Redirect(String url, Boolean endResponse)
at DotNetNuke.Modules.Admin.Users.Register.OnInit(EventArgs e)
at System.Web.UI.Control.InitRecursive(Control namingContainer)
at System.Web.UI.Control.InitRecursive(Control namingContainer)
at System.Web.UI.Control.AddedControl(Control control, Int32 index)
at System.Web.UI.ControlCollection.Add(Control child)
at DotNetNuke.UI.Modules.ModuleHost.LoadAjaxPanel()
at DotNetNuke.UI.Modules.ModuleHost.CreateChildControls()
at System.Web.UI.Control.EnsureChildControls()
at DotNetNuke.UI.Containers.Container.get_ModuleControl()
at DotNetNuke.UI.Containers.Container.ProcessModule()
at DotNetNuke.UI.Skins.Pane.InjectModule(ModuleInfo module)
Source: