Bought HD2 on ebay. Memory card had trojan. Help!

[bossb2525]

So I bought a used HD2 off of ebay and when I took the memory card out and placed it in my computer, my McAfee software detected a trojan on the card (don't have the name of the trojan now because I'm at work). It quarantined the trojan but I'm afraid to use the phone now. When I looked up the trojan last night it said it was a "low level threat" but then I looked at what it could do (steal passwords and take snapshots of computer screens). When I looked at the picture album on the phone, I noticed that it did save some of the webpages from the previous user's web browsing as a temp file. The phone had "third party apps" already installed on the phone but I'm sure I need to clear them all off. What steps do I need to do to ensure my information is safe? Thanks in advance.