I know this is old, but after going through some server logs, I came across the same parameters and I was curious where they were from.
I have found
When Googling them, all I found are Chinese websites. This matches with other log data though. Whether the users location was china, an article about china or reading in Simplified Chinese, many times link back to China.
Eventually found MicroMessenger being referenced, which is a client of WeChat social media platform. So with a high amount of certainty I think that this messenger app appends parameters to urls for the purposes of analytics.
No bug here.