It’s lucky for me to find this backdoor as there must be some programming error leading to the crash. There is no reason for China Unicom to show up when a user is importing account information of a totally irrelevant service. The only explanation is that it's trying to steal the data. But what's the motive?
ShadowsocksR is a VPN technology that can be used to falsify data streams. China Unicom is probably using this backdoor to capture those who are using ShadowsocksR to get free cellular data.
No matter what its purpose is, this is an act totally ignorant of user privacy, and apparently illegal. The ShadowsocksR configuration it’s been trying to steal contains user account information like account names and passwords. Who knows what other information it might be stealing secretly?
Shame on China Unicom and all those behind it.