A key takeaway from Bock’s instruction is that malware has evolved. While early viruses were often written for notoriety or vandalism, modern iterations are designed for profit and stealth.

In her sessions, Bock begins with the most common culprit: the computer virus. A virus is a piece of code that attaches itself to a legitimate program or file. It is fundamentally dependent on human action. Much like a biological virus requires a host cell to replicate, a digital virus needs a user to open an email attachment or run a downloaded file to spread. Bock illustrates how these programs can lie dormant for weeks, only "detonating" when a specific date is reached or a certain action is performed, leading to data corruption or system crashes.

A virus typically follows a specific path:

Unlike viruses, worms do not need human help or a host file. They exploit network vulnerabilities (like open ports or unpatched software) to travel from one machine to another automatically.