This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.
Opening an infected workbook and allowing the macro code to run will copy a loader workbook named "B00k1.xls" to the XLSTART folder. Any workbook opened on this, now infected, system will become infected.
Use current engine and DAT files for detection and removal.
It is very common for macro viruses to disable options within Office applications for example in Word, the macro protection warning commonly is disabled. After cleaning macro viruses, ensure that your previously set options are again enabled.
AVERT Recommended Updates:
* Malformed Word Document Could Enable Macro to Run Automatically (Information/Patch)