KABUL—The largest U.S. military base in Afghanistan was hit by a computer virus earlier this month that affected nearly three quarters of the computers on the base, U.S. News has learned.
This wasn't the first such cyberattack, and officials said that earlier incarnations of the virus had exported information such as convoy and troop movements here. It was not clear precisely what information, if any, was being pulled from Department of Defense computers by this latest virus, they said.
Officials familiar with the computer attack characterized it as extremely aggressive and said that it originated in China. However, they haven't been able to determine whether the viruses are part of a covert Chinese government effort or the work of private hackers.
U.S. military officials on the base took the step of prohibiting the use of portable flash memory, or "thumb drives," as they learned more about the virus. The move reflects the concern that the portable drives can inadvertently spread viruses through separate computer networks in the field. Late last week, Pentagon officials also banned the use of thumb drives because of concerns that they were spreading a virus through the Department of Defense computer networks.
U.S. military spokesmen at Bagram declined to comment, citing operational security.
But privately, U.S. military officials express grave concerns. The Chinese "learn a lot from these attacks," says one U.S. military intelligence official. "Like how our logistics and other systems work."