The U.S. Department of Justice has a special report, Violent Victimization Committed by Strangers, 1993-2010:

In 2010, males experienced violent victimizations by strangers at nearly twice the rate of females (figure 2). The rate of violence against males by strangers was 9.5 victimizations per 1,000 males in 2010 compared to 4.7 victimizations per 1,000 females.

It goes on to say that the disparity seems to be shrinking, with crime against men falling more rapidly than crime against women.