Stuxnet, a multi- component infection that has a worm, a worm assisting file and a rootkit that assists the worm in implementing the routines has infected SCADA systems in a typical way. The nature of Stuxnet itself reveals that it is not intended to affect home users or common domestic users. Worm_Stuxnet.A has looks for legitimate dll file S7OTBXDX.DLL which is used by Siemens WinCC systems in windows systems folder and renames it to S7OTBXSX.DLL then drops its copies in it and replaces the original file.
