Review: The Cuckoo’s Egg

While working in Infosec for many years, I only recently discovered “The Cuckoo’s Egg” (Doubleday, 1st edition) 🔗. I feel a bit ashamed for not knowing about it earlier, considering its fame. Nonetheless, as they say, better late than never. In the following lines, I’ll share my impressions after reading this (spoiler) amazing book.

Plot and Context

The story unfolds in Berkeley, CA, during 1986-87, specifically in the astronomy laboratory. There, the author, Clifford Stoll, known simply as Cliff, worked as a Systems Administrator for the Unix machines. Despite his background in astronomy, Cliff landed this job, and on his first days, he stumbled upon a discrepancy of 75 cents in the accounting system. This seemingly minor issue sparked his investigation, leading him to uncover that someone was exploiting the operating system and using their servers to pivot to military computers. As Cliff digs deeper, he finds himself caught up in an international espionage plot, tracking a hacker from Germany.

This book goes beyond Information Security (Infosec); it offers a fascinating account of a key era in Information Technology (IT). During this time, we witnessed the transition from mainframes to personal computers, the absence of a de-facto standard for Operating Systems (OSes), and the gradual emergence of Unix (with Linux not yet in existence). Ethernet was in its infancy, and other networking protocols such as X.25 held sway, particularly for long-distance communications (WAN). In fact, the term “Internet” was about to be widespread as the Arpanet and Milnet were the common terms to refer to this geographically distributed network of interconnected computers.

The state of Infosec during that era could be likened to that of an unborn baby. The Data Encryption Standard (DES) served as the default cryptographic algorithm, with little else available at the time. Networks operated largely on trust, as evidenced throughout the book, with many best practices that are now standard not yet established. Password sharing was common, Unix’s cryptographic implementation lacked salt, protocols lacked confidentiality and integrity controls, and default accounts remained enabled with default passwords—a chaotic landscape when viewed in retrospect.

Note

The context of the time matters. Implementing cryptography and other security controls back then often carried a heavy overhead that could render systems unusable on the processing power available. This constraint led to the development of secure protocols like SSL/TLS, DMARC/DKIM, IPSec, and SSH, which emerged later when technology had advanced to better accommodate such measures without compromising usability.

Impressions

Cliff’s writing style is so personable that you feel as though he’s a friend sharing his experiences with you. He skillfully weaves together the narrative of the investigation with glimpses into his personal life, allowing readers to empathize with him. There are moments when I found myself imagining what it would be like to walk in his shoes — sleeping at work for days on end, spending entire weekends tracking the hacker (my wife would kill me).

The author’s energy, curiosity, and eagerness to learn are contagious. Without modern security tools, Cliff is remarkably resourceful. He builds a sniffer using a wiretapped computer and a printer, writes a firewall in C, and sets up a Security Information and Event Management (SIEM) system in Unix and C, complete with a beeper alert. He also builds a honeypot to keep the hacker connected so authorities can trace their activities. His way of tackling security problems shows real skill and dedication to the field.

His methodical approach is another strength. Cliff keeps a detailed logbook, updating and revisiting it regularly. In the end, this practice is key to catching the hacker. Many of his findings come from later analysis of his notes, which also serve as evidence against the hacker. His commitment to keeping thorough records helps solve the case and shows how much documentation matters in Infosec investigations.

Stoll’s lack of formal security training doesn’t stop him from acting on his goals. He uses his creativity and broad skill set to his advantage. Without help from official agencies, he forges his own path. He’s a one-man army, moving smoothly between roles such as Incident Responder, Threat Detection Engineer/Analyst, Cyber Threat Intelligence (CTI) Analyst, Programmer, Network Engineer, and Sysadmin, among others. His range of skills and his determination are an inspiring example of what one person can accomplish through sheer dedication.

Final Thoughts

“The Cuckoo’s Egg” is more than an Infosec tale; it captures the computer revolution of the 1980s. It gives readers a glimpse into the shift from the mainframe era to the microcomputer era. We see the early days of Unix, marked by a lack of standardization and a pioneering spirit among early adopters. Networks were still in their analog infancy, and the highly skilled people who worked through it, whom Stoll affectionately calls “wizards” and “dinosaurs,” were true hackers in every sense of the word. These were the people who wrote C programs to build firewalls and repurposed printers as sniffers.

“The Cuckoo’s Egg” goes beyond Infosec and computers; it becomes a gripping espionage thriller with elements of romance and comedy. For IT or Infosec enthusiasts, it’s a must-read, showing how technology evolved alongside a gripping story. But even for those outside these fields, the book is well worth reading for how well it entertains, with all its intrigue and humor. Tech aficionado or not, if you want a fascinating story, “The Cuckoo’s Egg” delivers. It’s surprising that Hollywood hasn’t brought this story to the big screen yet.

Cliff, you’re a wizard. Thank you for this.

If I have seen further it is by standing on the shoulders of Giants. — Isaac Newton