Write down what you remember about the attack, and don't clean up or shower until you have been thoroughly examined by the authorities. There are no guarantees. First, get away with the least possible amount of injury. Personal security is primarily common sense. It is also different for each individual, so each of us will have to make things work for our particular needs.
Most people are capable of protecting themselves effectively.
The trick is to stay as calm as possible so any counter measure is decisive. To defend yourself, you must use leverage, cunning, deceit, and surprise to your advantage. When assailants attack someone seated, they compromise their own balance by bending at the waist. The very act of grabbing the intended victim leaves the attacker vulnerable to a counter attack. This vulnerability may aid the intended victim.