A U.S. Congressman whose computers were hacked last year is warning that other members of Congress may be vulnerable to the same sort of attack.

In a letter obtained and published by the National Journal earlier this week (PDF), Rep. Frank Wolf (R-Va.) said that few members of Congress have attended classified briefings that were triggered, in part, by the attack on his computers from China last year.

"I fear that Members are no better informed today than they were before," Wolf wrote. Wolf called on House Speaker Nancy Pelosi to make the briefings mandatory.

Last year, the computers of Wolf and seven other representatives, as well as those in eight committee offices, were infected with a virus designed to covertly remove files and track what a user writes in email or text messages. After the hack, Wolf said that few of his colleagues understood that sensitive information contained on their computers was accessible to outsiders.