MSIL:Agent-Bun[TRJ]

What’s this trojan and How to del it?

Attach your logs. (MBAM, OTL and aswMBR…!!)
Instructions: http://forum.avast.com/index.php?topic=53253.0

I believe that’s a keylogger. However, I am unsure.

https://www.virustotal.com/en/file/1badc00fad97fc08aead2c5f7f7bb1130b9663776e14553304438384fe5cb0ff/analysis/

Follow asyn’s advice and attach your logs so it can be removed from your system.