This indicates an attack attempt to exploit an Insecure Deserialization Vulnerability in HP Intelligent Management Center.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application.
HPE Systems Insight Manager (SIM) 7.6.x
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.