You have already reformatted but some of the below information is still relevant to you.
Here are some thoughts I have put together for people who ask what they should do in light of the infection. Ultimately each user must decide for themselves what to do. Here are some things you might want to consider.
It is necessary for us to at least make you aware of the worse case scenario. This is because of the potential Backdoor Trojans bring with them, but it is not a determination on our part that your situation currently falls within this worse case scenario.
Ultimately it is a personal decision whether to reformat or not. What decision should you make to let you sleep well at night? It is different for different people. I will say whether rightly or wrongly most people decide to clean and not reformat, at least initially.
The only insight I can offer is how I evaluate the issue personally even though I have never had a Backdoor Trojan on my computer. One of the primary purposes for malicious software is to somehow separate you from your money. It seems reasonable to assume that a thief trying to take your money via a Backdoor Trojan will hit you hard, and quickly. Once your computer starts to act up and you become suspicious you have the opportunity to eliminate access to your computer and change the information taken, namely account and password information. The key to this, in my opinion, is whether or not you have noticed any irregularities in your banking or other financial institutions, or things like email and social network accounts (i.e. Facebook). If you have not seen any evidence of that then you may question whether your information has truly been stolen. If it seems it hasn't, and your critical information has been changed, it is reasonable to be more confident you are safe but you must stop short of claiming an absolute guarantee.
If, after careful consideration you decide not to reformat your computer it would be wise to continue monitoring your sensitive data and don't wait to address future symptoms on your computer which seem to be malware related.
The bottom line, the ONLY way to be absolutely sure to be rid of a Backdoor Trojan is to reformat. The decision is yours.
Let me know if you have any follow up questions or if there is anything else I can assist you with. When we conclude our time together I will provide some general information about computer safety.
If I do not reply within 24 hours please send me a Personal Message
"Lord, to whom would we go? You have the words that give eternal life. We believe, and we know you are the Holy One of God."