Ninjamailer.php

: It is frequently flagged as a "mailer" used by threat groups (such as those involved in "Operation Armor Piercer") to automate the delivery of maldocs and archives.

: Use a security scanner like Wordfence or Sucuri to check for other compromised files or backdoors. ninjamailer.php

: Check your server logs to see when the file was uploaded and from what IP address. : It is frequently flagged as a "mailer"

: Legitimate tools used for improving email deliverability or verifying email lists . Recommended Actions : Legitimate tools used for improving email deliverability

: Many security scanners will identify files with this name as unwanted or malicious scripts due to their use in unauthorized email campaigns. Distinction from Legitimate "Ninja" Plugins

: It is designed to mass-send emails, often bypassing standard server restrictions to facilitate phishing or malware proliferation.

If you found ninjamailer.php in your site's directory and did not put it there: