You should look through your access_logs from around the time you started having problems and see if you can see what they did. You should also talk to your host about this. There is no date in the database for when a plugin was installed or changed. You may look the pluginid up in the database and then look through your Control Panel logs to see when that plugin was accessed/added/changed.
thanks for all the help , i checked and could not find anything i.e in Transaction Log /CP logs hope that what u mean by access_logs or else please advice what all I need to look and where they are found also precisely what needs to be checked
In the mean time can I delete the plugin indicted in the screenshot earlier? also have informed the host to run tests and inform me
during all this I observed another issue the thread/ post view counts are not increasing at all past 9-10 days is any file corrupted ? please guide how that needs to be fixed