Spent: verb, to spend, you could spend money settling a lawsuit but it would be a stretch to call that investment.
Investment: to allocate money in the expectation of future benefit, so that could mean administrative expenses, which would cover and include a lot (but not all) spending.
It's all about the perspective. A manager might consider test-driven development or security-driven development a matter of "spending" - in that it costs time and money and doesn't provide an immediate tangible benefit compared to making the thing that makes the money - but the engineers see it as an investment.
Both sides are right. If the company is never hacked, then it could both validate the security model as well as give a reason why not to bother in the first place. If the software runs smoothly throughout development (give or take a bug here and there), then all that testing was indeed a waste of time.
The difference between investment and cost is the ability to look into the future and analyze the past.
So there really isn't a straight answer.
EDIT: it also matters to the perspective of those outside of the organization. A bullish analyst might call Alphabet's moonshot projects an investment, while a bear would likely label them a cost.
in your example, even if the security-driven development generates value by preventing a hack, it could simply be considered Cost of Goods Sold, or maintenance costs...
In accounting standards, Investment turns into an asset.
-> CCTV system = investment
-> security guard = cost
they both generate value by increasing security and the dinstinction is not related to their usefullness for the company.
I define 'investment' as 'money spent in the pursuit of future benefit'. In this case, money spent settling a lawsuit to avoid a significant chance of later spending a far greater amount paid as damages (and why else would you settle?) is most definitely investment.
Investment: to allocate money in the expectation of future benefit, so that could mean administrative expenses, which would cover and include a lot (but not all) spending.
My vote would be on invested.