Good detection by Avast - detects JS:Agent-DPO [Trj] here...

See: https://www.virustotal.com/nl/url/c861f27a8379670df333f83b57347708b2451dde78c861f5f8511db78672088b/analysis/1450136046/
and https://www.virustotal.com/nl/file/0f7c94eb6e2ab685f61dcbb833cd0e3f40c1ea62b6f2a1a2ce4a175977c478ed/analysis/1449498680/
See: http://killmalware.com/southfloridasnorkeling.com/ &
Srange scripts in Header PHP! 79 mailcious files detected: http://quttera.com/detailed_report/southfloridasnorkeling.com

Read this: http://codex.wordpress.org/Hardening_WordPress.
WordPress Version
4.3.1
Version does not appear to be latest 4.4 - update now.

Warning User Enumeration is possible
It is recommended to rename the admin user account to reduce the chance of brute force attacks occurring. As this will reduce the chance of automated password attackers gaining access. However it is important to understand that if the author archives are enabled it is usually possible to enumerate all users within a WordPress installation.

Warning Directory Indexing Enabled
In the test we attempted to list the directory contents of the uploads and plugins folders to determine if Directory Indexing is enabled. This is an information leakage vulnerability that can reveal sensitive information regarding your site configuration or content.

/wp-content/uploads/ enabled

uBlock₀ has prevented the following page from loading:
-http://pagead2.googlesyndication.com/pagead/show_ads.js
Because of the following filter
-||pagead2.googlesyndication.com^
Found in: EasyList • hpHosts’ Ad and tracking servers • MVPS HOSTS

polonus (volunteer website security analyst and website error-hunter)