Common threats

4. Passive attacks

Security and privacy are also often confused, because you need security to obtain any semblance of privacy: Using tools—even if they're private by design—is futile if they could be easily exploited by attackers who later release your data. However, the inverse isn't necessarily true: The most secure service in the world isn't necessarily private. The best example of this is trusting data to Google who, given their scale, have had few security incidents by employing industry-leading security experts to secure their infrastructure. Even though Google provides very secure services, very few people would consider their data private in Google's free consumer products (Gmail, YouTube, etc.)

When it comes to application security, we generally don't (and sometimes can't) know if the software we use is malicious, or might one day become malicious. Even with the most trustworthy developers, there's generally no guarantee that their software doesn't have a serious vulnerability that could later be exploited.

To minimize the damage that a malicious piece of software could do, you should employ security by compartmentalization. For example, this could come in the form of using different computers for different jobs, using virtual machines to separate different groups of related applications, or using a secure operating system with a strong focus on application sandboxing and mandatory access control.