What are the odds of Backdoor/Spyware being implemented in Lightning port accessories?

[Bympolo]

I wonder how are the odds for vendors of Lightning port peripheries to place in periphery firmware / to periphery flash a secret backdoor, spyware, other malware. Specially those on open word market. How much do Lightning and apps interfaces protect from implementing code these kinds?
As of time being we wonder this for our new low-price level Lightning SD card reader bought on Amazon. It doesn't seem to be Apple genuine. Anyone likes to share own opinion?

 

[bakron1]

I quit worrying about all that stuff anymore, I use good passwords, stay off of sites known to have malware and only use apps I have used for many years and so far it’s worked great.

I have come to the conclusion that in this day and age, no device is 100% safe and every day it seems like I am reading about another app or email that contains malware.

I don’t accept any attachments and unless I know where and when the email and attachment originated from and by who, I just delete, that also goes for text messages.