This indicates an attack attempt to exploit a Cross-Site Scripting Vulnerability in WordPress Project Download Monitor Plugin for WordPress.
The vulnerability is due to insufficient sanitization of user-supplied data in post_title parameter. A remote, authenticated attacker can exploit this vulnerability by sending a specially crafted request to the target server. Successful exploitation could result in arbitrary script code being executed in the security context of the browser.
WordPress Project Download Monitor Plugin for WordPress before 4.4.7
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.