Serialized-object interfaces in certain IBM analytics, business solutions, cognitive, IT infrastructure, and mobile and social products allow remote attackers to execute arbitrary commands via a crafted serialized Java object, related to the InvokerTransformer class in the Apache Commons Collections library.
https://www.netwitness.com/wp-content/uploads/FIN13-Elephant-Beetle-NetWitness.pdf
https://f.hubspotusercontent30.net/hubfs/8776530/Sygnia-%20Elephant%20Beetle_Jan2022.pdf
http://www-01.ibm.com/support/docview.wss?uid=swg21972799
http://www-01.ibm.com/support/docview.wss?uid=swg21971758
http://www-01.ibm.com/support/docview.wss?uid=swg21971376