Final answer:
A self-replicating program that spreads into other software and systems is known as a computer virus, which poses significant cybersecurity threats, including information theft and communication disruptions.
Step-by-step explanation:
A computer program that copies itself into other software and can spread to other computer systems is called a computer virus. These malicious programs can infiltrate systems and networks, potentially leading to the theft of sensitive information, disruption of communications, and the spread of disinformation. The increasing use of cyberattacks by governments and militant groups highlights the importance of cybersecurity measures to protect against hackers exploiting vulnerabilities for espionage or sabotage.