SQL Query in suspended state causing high CPU usage
Although you've accepted an answer that informs you how to kill the session, this is a kind of problem that could repeat itself and so you should probably be aware that the CXPACKET wait type in itself is not a problem, but tends to indicate an issue with the execution of a parallel query.

Brent Ozar has posted a good explanation (with a video) of what a CXPACKET wait is and how you go about reducing them. As an example, if your parallel query runs across 5 CPUs and 4 of them have completed their allocated workload, the waiting on the 5th CPU to complete is what is identified as the CXPACKET wait.

You can start to alleviate CXPACKET waits by looking into setting the Maximum Degree of Parallelism (MAXDOP) on the individual query and/or the Cost Threshold for Parallelism on the instance, both of which are explained in the article.