xbindkeys and messed up outputs

I am trying to set some key bindings inside a virtual machine. So I did xbindkeys -mk and started testing keys. The result was somehow not what I expected: Left wind key ===> m:0x50 + c:115 Mod2+Mod4 + Super_L x ===> Mod2+x ctrl+left-win+x ===> m:0x54 + c:53 Control+Mod2+Mod4 + x First, what should I put in the xbindkeyrc and second, why do I get this output?