neither of the files are of plugin distro. do you have an updated wordpress? (4.4.1)
Do you have cache enabled in the plugin?
The plugin never uploads or changes any files when cache is disabled. When cache is enabled it stores files with mime check and code controlled file names which can never have .php extension. My guess is that some other plugin got hacked
Please send me the list of plugins that you use
As for now, just reinstall the plugin from the wordpress.org
