Which of the following describes a Trojan?

A Trojan is defined as a seemingly harmless application that can cause significant harm once executed. Unlike viruses and worms, Trojans do not self-replicate or spread themselves through networks. They often masquerade as legitimate software or are embedded within other software to deceive users into installing them. Once installed, Trojans can facilitate unauthorized access, data theft, or the installation of additional malicious software onto the system, thereby compromising security. Understanding this characteristic is crucial for recognizing the risks associated with downloading and running unfamiliar applications, as many attacks leverage the Trojan tactics to infiltrate systems.