Read on the attack (from 2 years ago): https://wordpress.org/support/topic/functionsphp-files-hacked
Recent attack reported via Ninja FW: http://ninjafirewall.com/malware/index.php?threat=2015-04-05.8
Site now cleansed: http://killmalware.com/nano-bsm-now.com/#
Wordfence installed can scan all the files looking for changed code…
See: http://ninjarecovery.com/malware/index.php?threat=2013-05-05.02
polonus (volunteer website security analyst and website error-hunter)