Sorry about your loss dear
Was it 10w40 or 5w30 ??
Are you sure your car wasnt consuming engine oil before ?? Any unusual or abnormally excessive smoke greyish white or white smoke for 20 to 25 mins on a cold start during the last 6 months ?
What viscosity were you using before this hyundai xteer ?? If you were using 20w50 ( recommended by toyota dealerships ) or 10w40 and after so many years you get less viscous and thin oil then this may happen not 100% sure but this is what I think
And yes it could be fake engine oil
May ALLAH PAK keep us all safe