I assume Hondaman means Adaware I used to use it but found Malwarebytes to be better

Both will work Ok with your other stuff.

The problem is you can never be absolutely certain that you don't have some key-logger lurking, so its best to take extra precautions as well

Whenever I need to type something as sensitive as this into my PC, I always do it in stages. Firstly, in advance and with IE etc closed, I type the number, and all other relevant data (end date, name, security code) into either a spreadsheet or Word document and save it in an encrypted location on my HDD. When entering data, I don't do it in order (first few characters of number then security number then few more character of number then date etc.)

Then, when I need to enter the data I open the site and use copy and paste to enter the data as required to the site.

If both of your security programs are freebies maybe time to Buy a decent one.You can get Emisoft cheap till Monday from my thread on the Helproom.

Never known anything to get past it yet anything dodgy and it will not let you open it.If you do open anything it will either give you a warning but usually removes it on the spot.

Of course there is always Malwarebyter Pro for a one off payment but I prefer the first one.

Have you purchased anything recently,or removed cash from a cash point.Bought anything from the Internet.

If you use your card in a shop that you do not normally use make sure you don't let the card out of your site in case it is swiped under the counter.

If none of those maybe you need to go to the Malware removal Forum and get them to check your computer out.

http://malwareremoval.com/forum/ Just explain your problem and they will take you through all of their procedures to make sure your computer is clean.