"crazytan" is the LinkedIn profile of a security software engineer named Jia Tan in Sunnyvale working at Snowflake, who attended Shanghai Jiao Tong University from 2011 to 2015 and Georgia Institute of Technology from 2015 to 2017. However, this Jia Tan on LinkedIn might not be the same Jia Tan who worked on XZ Utils. Also, the person who inserted the malicious code might be someone else who hijacked the account of the Jia Tan who worked on XZ Utils.