After Update: File Change Warning?

Is this a security problem oder caused by the update to itheme?

After Update i received this e-Mail:

Toppic: WordPress File Change Warning Wednesday, March 26th, 2014 at 9:14 pm UTC

A file (or files) on your site at http://***mysite.com*** have been changed. Please review the report below to verify changes are not the result of a compromise.

[ 350 lines of code moderated, that’s just way too much. For that many lines of code please use pastebin.com instead. ]

https://wordpress.org/plugins/better-wp-security/