Answer
The detection failure was caused by the failure to detect the attachment name. This failure to detect the attachment name was the result of spaces between field name ‘name’ and value separator ‘=’. This is considered to be malformed MIME and is not created by normal mail clients. Here is an example of the malformed MIME encoding:
Content-Type: audio/x-wav; Name = "README.EXE"
We have now changed the way we handle white spaces between field name and equals sign and this executable is correctly detected and blocked with or without inline scanning activated.
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Keywords:braid nimda malformed MIME anti virus