Many users are facing RPC-related errors while using Polygon and Fantom blockchains. The issue is related to the public RPC gateway provided by Ankr for Polygon (polygon-rpc.com) and Fantom (rpc.ftm.tools). It seems like the gateways were compromised via DNS hijack.  

Mudit Gupta, the CISO at Polygon, confirmed the same through a tweet. At the time of writing, he advocated users choose an alternative RPC gateway from Alchemy or others. He also informed users that Polygon is working on a decentralized alternative. More updates can be expected from them.  

Some Twitter users reported they were shown popups asking them to reset their wallet by sharing the seed phrase. Hence, users should be more careful and never share their seed phrases for whatever reasons. It's better to watch the latest updates from the official social media handles of Polygon and Fantom.  

Here's a Twitter thread that discusses what really happened and some temporary solutions.