I had three of these once. The bank asked me about them and explained someone has my card number and is testing it to see if it works (just verifying that the little charges go through) – so then they can then make a big purchase. The card needed to be canceled immediately and a new one issued, before a big purchase is made. Then it would try to charge with a declined card.
The amounts are so small you might not notice them. My little charges were for “Netflix” but I had no Netflix account. Even if I did, these charges in those amounts would be off of what is for renting a movie. They were bogus charges and were reversed after a fraud report was made.
Check your accounts often – I do daily (it only takes a few seconds). I always look at prior purchases to make sure I agree with them. I write down the daily amount on my phone note then keep track of what I spend from there. If I notice the amount each day is looking off, I know something is wrong and go looking for charges made. Then, if bogus or little charges show up, I will call the bank and decide to cancel my card and reissue a new one. Sometimes the bank can issue a temporary card, but I can use a different credit card or checkbook in the meantime.
A good bank will work with you to make sure you are not compromised. Between setting up a notification for any purchases over $75 (for example), to setting up your card to work in another state when on vacation, to calling or texting you at a store if something seems fraudulent, to knowing when to cancel your card – protect yourself and let them protect you.
Don’t let scammers take advantage of you – you need to know what your banking history is to keep on top of the scammers. Check your accounts often – it only takes a few seconds.