A computer virus has hit the U.S. Department of State, affecting the performance of the government's information technology system that manages visa approvals, according to reports. The virus shut down the State Department's Consular Lookout and Support System (CLASS) on Tuesday, according to published reports from Reuters and the Associated Press. A State Department representative CNET News.com reached Wednesday would not confirm that the system had crashed but indicated that IT personnel were working on a problem.

Late Wednesday, the State Department provided more details of the incident. According to spokeswoman Joanne Moore, at 4:30 a.m. Tuesday morning, the department's IT workers discovered the Welchia worm virus on an "unclassified open network" area of the CLASS system and began taking measures to contain the attack. At that time, the State Department sent a message to employees around the world warning them that CLASS was being temporarily shut down in order to prevent Welchia from spreading. However, Moore indicated that the virus never truly infiltrated CLASS.