There is no such thing as fraudulent transaction on bitcoin network, and there is no such thing as balance on the bitcoin network.
Read
this post explaining the transaction confirmation process.
Okay, but there can be counterfeit coins, no?
I'll read your link; thanks
No...
All "coins" are accounted for... they had to be "found", and only exist because they were "found", to begin with.
Finding a coin is not "fraud", it is called "reward" for "mining", and for tracking/encoding/decoding the billions of individual transactions along the way...
You can't "inject" coins into any transaction that didn't "come" from somewhere... Besides altering the other people's data, which would fail that altered block, you would still have to have that "found" bitcoin to inject... and if you "found it", then it isn't fraud... (It's a loop!)
There is a fixed number of coins that can EVER be found, and they are self-regulated by the discovery process itself. The faster we find them, the harder they get to find. The more of them there are that are found, the less of them there are to find...
Once ALL are found... there will HAVE to be a transaction-fee demanded for all transactions, otherwise no-one will have incentive to run the system that delivers transactions. Again, that is a self-regulating system.***
***Or they have to change the "code" to allow "111111111111djsljfsdfosduf8sd7f98" instead of the "000000000000000dfssd897f69s" hashes we find now. (Zero's lead-in to all hashes, that is what makes them difficult to find, and unique.)