Macros & Fsecure

[NielsOestergaard]

I have an Excel project with a lot of VBA macros.
I've just added a macro to save attachments from Outlook in a folder - and now Fsecure believes my Excel file is dangerous and puts it in quarantine.
The funny thing is, an Excel file with ONLY this macro in it is OK, and an Excel file with all my OTHER macros in it is OK. Among the other macros is one to execute DOS commands.
I copy-paste the macros via a text editor, so it's NOT - I believe - because some foreign code sneaks in without me noticing it.
Fsecure is using "heuristics", and I suppose it works a bit like a spam filer: Any file will score points based on several different criteria, and if it exceeds a treshold, it will be deemed dangerous.
I could post my macros here, but what I really want to know is, do anyone have guidelines, do's and don'ts, about this? Or similar experiences? In the end, my Excel project will be used by others, and I do not know what security software they will have.

[NielsOestergaard]

Please Login or Register  to view this content.

[NielsOestergaard]

Please Login or Register  to view this content.

[NielsOestergaard]

Please Login or Register  to view this content.

[NielsOestergaard]

Please Login or Register  to view this content.

[NielsOestergaard]

So I've stripped down the offending code to the four sections posted above. Combining these four, and no other content, in a VBA module, results in an Excel file that Fsecure promptly removes. Leaving out ANY of the four sections makes the file palatable to Fsecure. Section 4, in particluar, should in my opinion be of absolutely no relevance to Fsecure, so I think (once other aspects of the macro cause concern) the AMOUNT of code in itself contributes to the score that makes Fsecure reject my file. (Also, simplifying Section 2 (harvesting mail attachments) so that it still does exactly the same thing, but without keeping track of attachment filename extensions that I skip, makes it OK.)

It's all pretty annoying! Does anyone have any ideas how to move on with my project? I need to download attachments (Section 2), to execute a DOS command (Section 1), and a lot more (Sections 3 and 4 are just a small sample)? I do have an idea: Move the harvesting to a separate Excel project that does this, and nothing else. I think that would work for me. But ... might Fsecure (or other malware detection software) still kill my whole project next time they update sth? (I THINK Fsecure accepted an essentially equivalent xlsm file early January; I only got into trouble this week!)