Today, many commercial PHP scripts (WHMCS, Laravel-based apps, custom frameworks) are still encoded with version 7.4 or similar. This is why you might encounter a file requiring the "IonCube Loader 7.4" or a specific decoder.
Academic research often examines IonCube within the broader context of PHP bytecode protection and deobfuscation. Security Analysis of PHP Bytecode Protection Mechanisms Ioncube Decoder 7.4
. It is frequently associated with "nulled" software—pirated versions of premium plugins or themes that have had their licensing checks removed. Security Risks many commercial PHP scripts (WHMCS