As an early contributor to ABAP2XLS...I think I need to chime in...
Back in my old consulting days...I used ABAP2XLS in two big and important Montreal/Canada customers...and achieve things that without...would be close to impossible...
Regarding malware of malicious code...well...ABAP is platform where if you don't hide a "DELETE * FROM TABLE XXX" then you can't possibly write destructive code...
That said...it's very easy and simple to either scan the source code or test it in a safer environment like a NetWeaver Sneak Preview or something...
To do my first and only contribution to the project...I need to inspect the source code and found nothing but beautiful code ready to make my life easier...
Making up numbers or even creating fake customer reviews is pretty easy...so being ABAP2XLS Open Source...just do what I did...read the code...search for "dangerous" pieces of code...test it...and then...use it 
Greetings,
Blag.
Development Culture.