Happy Drupal Security Update Day!
Everyone should take note : [after the update] "Additionally, it's recommended that you audit all previously uploaded files to check for malicious extensions. Look specifically for files that include more than one extension, like .php.txt or .html.gif"
"find . -name \*.html.\*" and "find . -name \*.php.\*” should do it.
Good Luck, be safe and
May the Force Be With You!