Understand why site is hacked and defaced....CMS & other insecurity!

Look here: http://killmalware.com/weinreporter.de/#
First the CMS issues: WordPress Version
3.6.1
Version does not appear to be latest 4.6.1 - update now.
WordPress version outdated: Upgrade required.
RevSlider Plugin outdated: Upgrade required.
Outdated WordPress Found: WordPress Under 4.6
Outdated RevSlider Found. Serious risk: Under 4.1.4

WordPress Plugins
The following plugins were detected by reading the HTML source of the WordPress sites front page.

jetpack 2.4.4 latest release (4.4.2) Update required
http://jetpack.com
simple-lightbox latest release (2.6.0)
http://archetyped.com/tools/simple-lightbox/
contact-form-7 3.5.2 latest release (4.6) Update required
http://contactform7.com/
revslider
Plugins are a source of many security vulnerabilities within WordPress installations, always keep them updated to the latest version available and check the developers plugin page for information about security related updates and fixes.

Warning User Enumeration is possible
The first two user ID’s were tested to determine if user enumeration is possible.

ID User Login
1 None wp-weinreporter-klaus
2 None klaus-d-weinreporter
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.

jQuery: -http://weinreporter.de
Detected libraries:
jquery-migrate - 1.2.1 :-http://www.weinreporter.de/wp-includes/js/jquery/jquery-migrate.min.js?ver=1.2.1
Info: Severity: medium
http://bugs.jquery.com/ticket/11290
http://research.insecurelabs.org/jquery/test/
jquery - 1.10.2 : (active1) -http://www.weinreporter.de/wp-includes/js/jquery/jquery.js?ver=1.10.2
Info: Severity: medium
https://github.com/jquery/jquery/issues/2432
http://blog.jquery.com/2016/01/08/jquery-2-2-and-1-12-released/
jPlayer - 2.2.0 : (active1) -http://www.weinreporter.de/wp-content/themes/halsey/js/jquery.jPlayer.min.js?ver=2.1.0
Info: Severity: high
http://jplayer.org/latest/release-notes/
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-2023
Info: Severity: high
http://jplayer.org/latest/release-notes/
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-1942
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-2022
(active) - the library was also found to be active by running code
3 vulnerable libraries detected

F-X-F-status: https://observatory.mozilla.org/analyze.html?host=weinreporter.de

Web site defaced. Details: http://sucuri.net/malware/entry/MW:DEFACED:01?v47
Hack via doubling Jetpack Open Graph Tags see line 55 in the source code - read about that threat:
https://wordpress.org/support/topic/remove-jetpack-open-graph-tags-with-og-tags-plugin/
and header_inner CSS pseudo-element hack. Malware Hidden Inside JPG EXIF Headers is also a possibility.

See: -https://aw-snap.info/file-viewer/?tgt=http%3A%2F%2Fweinreporter.de&ref_sel=GSP2&ua_sel=ff&fs=1

PHP vulnerable 5.3.29. Various issues: http://www.domxssscanner.com/scan?url=http%3A%2F%2Fweinreporter.de

→ -> https://aw-snap.info/file-viewer/?tgt=http%3A%2F%2Fweinreporter.de&ref_sel=GSP2&ua_sel=ff&fs=1

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

Another one where outdated WordPress also played a role: http://killmalware.com/jagt-polen.pl/#
bad web rep: -http://cloudserver113667.home.net.pl/
Hack via deprecated sidebar: https://aw-snap.info/file-viewer/?tgt=http%3A%2F%2Fjagt-polen.pl&ref_sel=GSP2&ua_sel=ff&fs=1
Outdated CMS: WordPress Version
3.8.16
Version does not appear to be latest 4.7 - update now.

2 vulnerable jQuery libraries: http://retire.insecurity.today/#!/scan/21954927d00451dba21cff44053d323e8d1626a98a5468df3ceaaa0d48c023dc

pol