Secondhand item came with previous owner's files on the SD card, do I return the card or format it?
I bought a 3d printer off Ebay which got delivered not too long ago, and it came with 2 sd cards - one with a build video and some demo print files, but worryingly another card that has all the previous owner's personal files on there.
Not sure whether to format it, or to contact the seller offering to send the card back (free of charge)... how would you prefer to be approached in a similar situation?
Edit: No gcode files are on the card, just 30gb of pictures, music and videos. Sent the seller a message offering to upload it to cloud or to send the card back
Firstly, never stick a storage drive into your personal machine that was previously owned by an individual. If you need to use the drive always open it on a machine disconnected from the Internet that contains no personal files. Better would be to boot up a live Linux machine and read the drive and format if needed.
It doesn't have to be about someone stealing your data. I had a situation where a user got some malware on their USB drive that deleted other user files when plugged in and replaced them with porn or something. It's just good practice to not plug unknown devices into your computer all willie nillie.
Windows doesn't autorun by default these days iirc, I don't think there's any zero interaction remote code execution bugs that are unpatched either. The only way you would get compromised is by running something or if the usb device pretended to be a keyboard which I don't think is commercially available in sd card format
As long as you don't open any executables, you'll be fine.
What's the chance that the seller has a 0day (which would be veeery valuable) and is using it to steal data from someone random? Not worth it for sure on their side.
It's entirely possible this drive was made maliciously to pass on data from whatever unsuspecting soul uses it. The seller op bought from could even be a victim themselves. You just never know.
The SD card is still speaking SD protocol, the card reader bridges between USB and SD.
This only works with USB sticks because they're plugged on directly over USB and you don't know whether it'll present itself as a storage device or as a keyboard that immediately starts typing stuff and running a bunch of commands.
The risk is not the flash storage part, it's the USB interface.
Best security practices are pointless if you disregard them because they're inconvenient and unlikely to be necessary. Most needles I find on the ground are clean too, but I'm not just gonna stick them in me because the odds are in my favor.