How do you know if your computer is vulnerable to cyber-attack? USCERT The U.S. Computer Emergency Readiness Team. says many computers are sold with software already loaded. Whether installed by a computer manufacturer, operating system maker, Internet Service Provider, or by a retail store, USCERT says the first step in assessing the vulnerability of your computer is to find out what software is installed and how one program will interact with another. Unfortunately, it is not practical for most people to perform this level of analysis.