Is this a genuine Marshmallow update, and how do I get rid of it?

[Keith May]

Hi,

This morning, my wife found this message on her phone (Galaxy A3 2016, sim-free, using UK Three PAYG sim card):



The message is preventing her from using the phone - all she can do is switch if off and back on again, after which the message reappears. She doesn't want to tap "INSTALL NOW" because
(1) She suspects it to be malware, as there's no option not to install it
(2) Even if it's genuine, she's perfectly happy with the phone as it is, and doesn't want to risk messing it up with an unnecessary update.

So my questions are:
(1) is this a genuine update or malware?
(2) how can we get rid of it?

Note, I have the same model of phone (but in black), bought a few weeks earlier, and I haven't had this message.

 

[Rukbat]

1) Yes.

2) You can't. Allow it to install, back up everything (see Backing up an Android Device) and flash the earlier ROM that you were running before (see [Samsung] How to flash Stock ROM via ODIN). If you can, flash a rooted ROM and disable the updater, otherwise it's just going to update again.

 

[Keith May]

Thanks for your reply! Phone still working fine after the update, so I'll keep it.

 

[keat63]

If it's not too late then you might get away with the following, but you will lose all your apps and contacts (if they are stored on the phone)
Maybe someone else might come along and tell me differently if this works.


Turn off the phone.
Remove the sim.
Press and hold home button, volume up and then power button.
Keep these pressed until you see 'recovery booting' using a combination of the volume buttons to scroll up and down, and the power button to invoke.
Choose 'wipe cache partition' and then 'factory reset' followed by 'reboot system now'

When the phone starts up, configure it as a new phone, but don't connect to wifi.
Go in to settings and turn off 'Auto Update'
Now refit the sim card and connect to wifi.