What Is Trojan Spyware?

Like spyware, Trojan programs (also known as Trojan horses) can sneak into your system and run without your knowledge. The Troy program can control multiple functions. For example, some Trojan programs can dial long-distance or toll numbers (similar to dialers) through the computer's modem, which may cause high call charges. Trojans, unlike viruses and worms, do not replicate themselves.