1. Open the apk as a compressed package, delete the original signature, and then sign it. The installation can be opened normally, but it is not normal to use IDE (that is, apk will automatically decompile dex) tools for secondary packaging, such as flashing back/popping up a non-genuine prompt box. It can be confirmed that it is the verification of dex file.

2. Open the apk in the form of compressed package, delete the original signature and then sign it. If it is not opened normally after installation, it can basically be concluded that it is a signature check. If there are anomalies when the network is disconnected, it is a local signature check; If the network is disconnected first, it is the signature verification on the server side.