Analyzing Suspicious Attachment

["Al Cooper" <cooper () hmcnetworks com>]

We had a user open a suspicious attachment.  The attachment did not open so
she sent it to two of her colleges.  One of her colleges was also unable to
open the file, but the third person did successfully open the file.  The
attachment did not match the original email and IT was eventually called, a
few hours later.  The three computer have been removed from the network. 

I have the attachment.  It is a zip file.  Inside the zip file is one .scr
file.  The antivirus (Symantec) did not catch anything when the file was
opened.  The email is an HTML email and there are pictures that can be
downloaded.

Outside of the obvious policy and training issues, what is the best way to
determine what if any damage has been done to the network?  What tools do I
need to analysis the attachment to see what it is and how it works?

Thanks for your help,




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