I was bored, so I decided to find out for you guys.

In the template postbit_attachment, find:
Code:
($attachment[filesize]<if condition="$show['views']">, <phrase 1="$attachment[counter]">$vbphrase[x_views]</phrase></if>)
Replace With:
Code:
($attachment[filesize]<if condition="$show['views']">, <phrase 1="$attachment[counter]">$vbphrase[x_views]</phrase></if>) (MD5: $attachment[filehash])