Description
WordPress Plugin Qualified Electronic Signatures by eID Easy is prone to a supply chain attack because of the Polyfill JavaScript library used. The ownership of the library was taken over by malicious threat actors that used the service to redirect victims to malicious websites. WordPress Plugin Qualified Electronic Signatures by eID Easy version 3.3.0 is affected; prior versions may also be affected.
Remediation
Manually remove the use of Polyfill.io from the plugin, or disable and remove the plugin until a fix is available
References
https://sansec.io/research/polyfill-supply-chain-attack
https://plugins.svn.wordpress.org/eid-easy-qualified-electonic-signature/trunk/readme.txt