The Supreme Court originally ruled in Massachusetts v Mellon and has held in United States v. Richardson that there is no general doctrine of "taxpayer standing." The majority opinion in United States v. Richardson states
The acceptance of new categories of judicially cognizable injury has not eliminated the basic principle that, to invoke judicial power, the claimant must have a "personal stake in the outcome, "in short, something more than "generalized grievances"...
In the Court's view, the collection and use of taxes is a political issue and not a judicial one except if it causes cognizable harm to the plaintiff (note that "cognizable" is not just "actual," it must also be something that exceeds the Constitutional authority of the government body in question, per Flast v. Cohen, although just being a taxpayer is enough to have standing if the expenditure is unconstitutional), in most cases the "harm" the plaintiff suffers by their tax money being spent in a disagreeable way is too far removed from them personally to be a cognizable harm. I'll note that the cases I've cited are suits against the Federal Government, but there's no reason they wouldn't apply equally to a suit against a state government unless there was a particular state law that gave more latitude to taxpayer standing, which I haven't been able to find for Florida.
Ultimately, what this means is that the Court's opinion is that in almost all cases, taxpayers need to have their grievances with tax expenditures resolved by their elected officials, not the court system. At this point we could talk about Sovereign and Qualified Immunity for the government body and official respectively, and whether or not the downloading of the malware would be negligence and allow a suit under Title XLV 768.28, which waives Sovereign Immunity for the Florida Government for torts related to (among other things) loss of property, but it would ultimately be fruitless since simply being a taxpayer is not enough to have standing for injury if the government uses the taxes in a way the plaintiff disagrees with.