This indicates an attack attempt to exploit an Command Execution vulnerability in multiple Foxit products.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted file.
Foxit Software Foxit Reader 220.127.116.1155 and earlier
Foxit Software PhantomPDF 18.104.22.16855 and earlier
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.