Creeper Virus

Definition of Creeper Virus

The Creeper Virus is considered one of the first computer viruses, originating in the early 1970s. It was designed to move between mainframe computers on the ARPANET, the precursor to the modern internet, and display the message “I’m the creeper, catch me if you can!” Despite causing no significant damage, the Creeper Virus marked the beginning of computer virus research and development of antivirus software.


The phonetic pronunciation of “Creeper Virus” is:Kree-pər Vahy-ruhs

Key Takeaways

  1. The Creeper Virus was one of the first computer viruses, appearing in the early 1970s and targeting the ARPANET (the precursor to the internet).
  2. It was designed as an experimental self-replicating program, rather than a malicious attack, and would display the message “I’m the creeper, catch me if you can!” on infected systems.
  3. The development of Creeper led to the creation of the first antivirus software, called Reaper, which was designed to find and remove the Creeper virus from infected systems.

Importance of Creeper Virus

The Creeper Virus is an important term in the technology world as it represents a significant milestone in the development of computer viruses and cybersecurity.

Created in the early 1970s by Bob Thomas at BBN Technologies, Creeper Virus was one of the first self-replicating programs, laying the groundwork for modern computer worms and viruses.

It primarily spread on the ARPANET network, displaying a simple message, “I’m the creeper, catch me if you can!” Although it didn’t cause any significant harm or damage to the computers, it raised awareness about the potential threats posed by such malicious software.

Consequently, Creeper’s existence led to innovations in detecting and countering similar programs, signaling the birth of the field of cybersecurity and the ongoing efforts to protect digital information systems from emerging threats.


The Creeper Virus, often considered as the first computer virus in history, was developed with an experimental purpose, aiming to explore the functionality and potential impacts of self-replicating programs on computer systems. Developed in the early 1970s by Bob Thomas, an engineer at BBN Technologies, the Creeper Virus was designed to exhibit autonomous behavior in order to move through the ARPANET—the predecessor to the modern internet. The primary aim behind this creation was to analyze the spread and impact of this self-replicating entity on interconnected computer networks.

This study was vital in understanding network security in the context of a massively growing digital landscape and helped set the stage for the development of security protocols and countermeasures. Although the Creeper Virus was non-malicious by design, its functionality prompted computer scientists to deal with the ramifications of invasive software on multiple systems. Once active, the virus displayed the message “I’m the creeper, catch me if you can!”, while jumping from one system to another within ARPANET.

This behavior demonstrated how the unauthorized transfer of files and data could disrupt the normal functioning of a computer network. Consequently, the results of this experiment lead to the creation of the first anti-virus, Reaper, which was designed specifically to remove the Creeper Virus. This milestone in computing history underlined the need for constant advancements in digital security and protection against harmful software that could jeopardize the integrity of computer networks and systems.

Examples of Creeper Virus

The Creeper Virus was an early form of computer viruses that emerged in the early 1970s. Although it is not actively present in the real world today, there are some noteworthy instances and facts:

ARPANET Infection: Creeper was primarily developed to demonstrate the possibility of a self-replicating program within a network of interconnected computers. The Creeper Virus first infected a mainframe computer connected to ARPANET, the predecessor to the modern internet. This showed that a virus could be transmitted between computers in a network, which was an important discovery at the time.

Data General Nova Computers: The Creeper Virus was designed to target the then-popular Data General Nova computers running the TENEX operating system. The virus would occasionally display the message “I’M THE CREEPER: CATCH ME IF YOU CAN” on the teletype terminal. This played a role in inspiring the development of other self-replicating programs and computer viruses.

Reaper Program: After the emergence of the Creeper Virus, a program called “Reaper” was developed to delete or “kill” Creeper instances on infected systems. Reaper can be considered as an early example of antivirus software, showcasing the potential for creating countermeasures to deal with malware and other malicious programs.While the Creeper Virus itself does not have active real-world examples in today’s world, its historical significance paved the way for understanding computer viruses and the development of antivirus software.

FAQs on the Creeper Virus

1. What is the Creeper Virus?

The Creeper Virus is considered to be one of the first computer viruses in history. It was created in the early 1970s by Bob Thomas and targeted mainframe computers. The purpose of the virus was to experiment with self-replicating programs and examine their potential impact on computer systems.

2. How does the Creeper Virus work?

The Creeper Virus infects a system by searching for a specific program, known as “Earliest Version”. Once found, it duplicates itself while displaying the message, “I’m the creeper, catch me if you can!” The virus then searches for other computers on the network to spread to, constantly replicating itself as it moves from system to system.

3. How did the Creeper Virus spread?

The Creeper Virus spread via ARPANET, which was the precursor to the modern-day Internet. It infected DEC PDP-10 mainframe computers running the TENEX operating system. As it spread through the network, it would jump from one computer to another, replicating itself along the way.

4. What impact did the Creeper Virus have on computer systems?

While the Creeper Virus was not intended to be malicious, it did demonstrate the potential for self-replicating programs to cause widespread impact on computer systems. However, being an experimental program, the virus did not wreak havoc on the systems it infected. The importance of the Creeper Virus lies in its role in the development of computer security and the study of computer viruses.

5. How was the Creeper Virus stopped?

A program called the “Reaper” was created by Ray Tomlinson, the same person who developed the email system. The Reaper program was designed to locate copies of the Creeper Virus and delete them from the infected systems. Eventually, Reaper was successful in eradicating the Creeper Virus from the ARPANET.

Related Technology Terms


  • First computer worm
  • 1971 ARPANET
  • Ray Tomlinson
  • Reaper Virus
  • Experimental self-replicating program


Sources for More Information


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