Hi Dan,
thank you for your post and sugestions...
I have already another anti-malware, I desinstall and install Anti-Malware and Brute-Force by Eli.
This plugin show me some files with problem and two of this files, marked with "Potential Threats", are:
.../portfolio-gallery/admin/portfolios_view.php
.../portfolio-gallery/elements/jscolor/jscolor.js
i deleted all files with Backdoor Scripts and Known Threats ..