it is a simple heuristic with 2 boolean switchesI have doubts it is using any heuritisc; if using, it can find the app fine, even if not installed from the store; not all standalone apk is malicious.
What makes sense more, it is checking some metadata related to Google store, which get added upton install from there.
Something like
yada yada yada (check this, check that)
If (isSideloaded && canDrawOverApps) {invokeBlockAccess()}.
It still classifies as heuristic because it is not a universal rule set in stone, rather it is a “good enough for the task” rule that the developer came up with and implemented.
I wouldn’t be worried about the banks, none of the major or even minor bank/virtual bank/building society is close to bankruptcy.So, in short, the banks will cover their losses via crowdsourcing via fees & charges. All of us cover the banks' losses because some users get fooled.
They are already saving up on interest rates, staff, offices, support and many other costs.
They generally do not charge users fees here (unless when they offer bells and whistles like insurances and so on), but there are many charges for businesses, transaction disputes and so on.

