Nitro attacks

The attacks were traced back to a computer system that was a virtual private server (VPS) located in the United States. However, the system was owned by a 20-something male located in the Hebei region in China. We internally have given him the pseudonym of Covert Grove based on a literal translation of his name. He attended a vocational school for a short period of time specializing in network security and has limited work experience, most recently maintaining multiple network domains of the vocational school.
Covert Grove claimed to have the U.S.-based VPS for the sole purpose of using the VPS to log into the QQ instant message system, a popular instant messaging system in China. By owning a VPS, he would have a static IP address. He claims this was the sole purpose of the VPS. And by having a static IP address, he could use a feature provided by QQ to restrict login access to particular IP addresses. The VPS cost was RMB200 (US$32) a month. While possible, with an expense of RMB200 a month for such protection and the usage of a US-based VPS, the scenario seems suspicious. We were unable to recover any evidence the VPS was used by any other authorized or unauthorized users. Further, when prompted regarding hacking skills, Covert Grove immediately provided a contact that would perform ‘hacking for hire’. Whether this contact is merely an alias or a different individual has not been determined.

It is from symantec.

I want to know what is the advantage of VPS for this operation?May you explain about VPS?