It maybe a rebuild with a professional respray.
It appears to have twist grips gears, which on a road bike means only thing, (BSO), as S-Express says above.
I can't imagine anyone doing a professional respray on such a bike
More likely it's nicked and the decals have been removed to try and prevent identification
If buying second hand there's no shortage of great quality bikes out there, you just need to know what to look for.
@biggs682 is our resident purveyor of all things pre-loved
[EDIT] We x posted there so I didn't realise you'd already bought it
At least you seem aware of what it actually is, so you've bought with your eyes open.
Enjoy but don't go mad with upgrades, (or even bother TBH), better to move it on when your ready and replace it with something more suitable to an upgrade or two.