Both Trojans and malware represent a real danger to the security of end users systems. If an attacker can trick or seduce a user to install one of these programs the hacker may gain full control of the system. Much of this malware works under the principle of “you cannot deny what you must permit.” Meaning that these programs use ports like 25, 53, and 80. Ports the administrator usually has left open. If the programs don’t use these ports the hacker always has the option of using port redirection or covert communication channels. These are the reasons these programs can be so dangerous.

What is a covert channel? A secret unknown communication channel that is not prevented or secured.
 

What is a macro virus? A virus written using a macro language within a productivity document.

Have any viruses, worms, or bots been developed for cell phones?  Yes, Sexy Space is considered by some to be the first cell phone bot.
 

What role can SSL, SSH, and TLS play in covert channel communication? Secure tunnels to bypass filters.
 

I heard the term Sheepdip mentioned.  What does that mean? Sheepdip is a stand alone system used to scan all media and devices as they come in from outside an organization’s security perimeter to detect malware before the media or device is approved to connect to the internal network.