Exactly what I reported on Tuesday would happen, is happening now.
When on Friday, it was reported, "that a massive wave of cyber attacks swept across 99 countries, possibly including Australia, with cyber security experts claiming it could be the biggest attack of its kind ever recorded."
What happened is that a major hole has been discovered in the antivirus software, and many virus developers are now rushing in to take advantage of this hole. Since Point of Sale software is a very attractive target because of credit card's transactions, you can be assured that you will be targeted.
The solution is simple, update your antivirus software ASAP.