The Most Impactful Computer Crimes In Digital History
by Scott
Over the last several decades, computer crime has evolved from small scale curiosity driven intrusions into large scale operations capable of reshaping global politics, destabilising economies, and permanently altering how digital systems are designed and defended. The most significant computer crimes were not merely acts of theft or vandalism but carefully orchestrated campaigns that combined deep technical knowledge with strategic intent. Some were financially motivated, some ideologically driven, and others designed to quietly sabotage infrastructure while remaining invisible for years. Together, they represent milestones in the history of cybercrime and cyber warfare.
One of the earliest computer crimes to demonstrate true global impact was the Morris Worm in 1988. Although primitive by modern standards, it was the first worm to spread autonomously across the early internet. Created by Robert Tappan Morris, a graduate student at the time, the worm exploited vulnerabilities in Unix systems using techniques such as buffer overflows and password guessing. The intent was not financial gain or sabotage but experimentation and measurement of the internet’s size. However, a design flaw caused it to reinfect systems repeatedly, consuming processing power and effectively shutting down large portions of the network. The resulting disruption forced system administrators across universities and research institutions to disconnect machines, marking the first widespread denial of service incident. The Morris Worm led directly to the creation of the Computer Emergency Response Team concept and demonstrated that software flaws could have cascading systemic consequences.
As the internet matured, criminal activity became more organised and profit driven. The rise of the ILOVEYOU virus in 2000 illustrated how social engineering could outperform technical exploits. Written in Visual Basic Script and distributed via email attachments, the malware masqueraded as a love letter and relied on human curiosity rather than software vulnerabilities. Once executed, it overwrote files, harvested email addresses, and propagated itself aggressively. The damage was immense, with millions of computers infected globally and billions of dollars lost due to cleanup, downtime, and data destruction. The perpetrators exploited weak email filtering and user trust rather than advanced exploits, proving that human behaviour was often the weakest link in security chains.
Financially motivated cybercrime reached a new level with the emergence of organised banking malware in the mid 2000s. One of the most damaging operations was the Zeus malware ecosystem. Zeus was not a single attack but a toolkit sold and modified by multiple criminal groups. It used keylogging, form grabbing, and man in the browser techniques to silently intercept banking credentials. Zeus infected millions of machines worldwide, enabling large scale fraud across thousands of financial institutions. The modular nature of the malware allowed attackers to update functionality rapidly, evading detection while targeting specific banks and payment systems. Zeus fundamentally changed online banking security and forced widespread adoption of multi factor authentication and behavioural fraud detection.
State sponsored cybercrime emerged unmistakably with the discovery of Stuxnet around 2010. Unlike financially motivated malware, Stuxnet was designed for precision sabotage. It exploited multiple zero day vulnerabilities in Windows systems and used stolen digital certificates to appear legitimate. Its payload specifically targeted Siemens industrial control systems, manipulating programmable logic controllers while reporting normal operational data to monitoring software. This allowed physical centrifuges to be damaged without immediate detection. The attack required intimate knowledge of industrial processes and demonstrated that malware could cross the boundary between digital systems and physical infrastructure. Stuxnet marked the first known instance of a cyber weapon causing real world equipment destruction and set a precedent for future cyber warfare.
Following Stuxnet, destructive malware became an accepted tool of geopolitical conflict. The Shamoon attacks against Saudi energy companies demonstrated a willingness to cause overt damage rather than covert sabotage. Shamoon wiped hard drives and replaced master boot records with politically charged imagery, rendering tens of thousands of machines unusable. The attack disrupted operations for weeks and required extensive system rebuilds. Unlike espionage focused malware, Shamoon made no attempt to hide, instead aiming to maximise disruption and psychological impact. It highlighted the vulnerability of corporate networks even when disconnected from the internet through internal trust relationships.
Large scale data breaches became another defining category of computer crime. The breach of Equifax in 2017 exposed sensitive financial information of approximately 147 million people. The attack exploited an unpatched vulnerability in a widely used web application framework. Once inside, attackers moved laterally through poorly segmented networks, accessing databases containing social security numbers, birth dates, and credit histories. The breach persisted for months without detection, revealing failures in patch management, monitoring, and internal access controls. The financial and reputational damage was immense, leading to regulatory scrutiny and reshaping data protection expectations worldwide.
Another watershed moment in cybercrime was the WannaCry ransomware outbreak in 2017. WannaCry exploited a vulnerability in the Windows Server Message Block protocol, using an exploit originally developed by a nation state and later leaked. The malware spread autonomously across networks, encrypting files and demanding payment in cryptocurrency. Hospitals, transportation systems, and manufacturing facilities were severely impacted. The attack demonstrated how leaked offensive cyber tools could be repurposed for indiscriminate criminal use. It also exposed the dangers of legacy systems that could not be easily patched, particularly in critical infrastructure environments.
The NotPetya attack later that same year illustrated how cybercrime could masquerade as ransomware while serving destructive geopolitical goals. Initially distributed through compromised accounting software updates, NotPetya spread rapidly using credential theft and network exploits. Unlike true ransomware, it irreversibly destroyed data, making recovery impossible even with payment. The attack caused billions of dollars in damage across multinational corporations, disrupting shipping, manufacturing, and logistics worldwide. NotPetya blurred the line between crime and cyber warfare, as its impact extended far beyond its original target region.
Supply chain attacks emerged as one of the most sophisticated forms of computer crime with the SolarWinds incident. Attackers compromised the build environment of a widely trusted network management platform, inserting malicious code into legitimate software updates. Thousands of organisations installed the compromised updates, granting attackers long term access to sensitive networks. The attack emphasised the fragility of trust relationships in software ecosystems and demonstrated how attackers could achieve massive reach by targeting a single upstream provider. Detection was delayed for months, during which attackers conducted espionage with extreme care to avoid triggering alerts.
One of the most financially devastating cybercrime campaigns was the Bangladesh Bank heist in 2016. Attackers gained access to internal banking systems and manipulated SWIFT messaging infrastructure to initiate fraudulent transfers. By understanding internal workflows and timing, they successfully moved tens of millions of dollars before detection. The attack combined technical intrusion with deep knowledge of financial operations, highlighting that cybercrime often succeeds by exploiting process weaknesses rather than purely technical flaws.
Across all of these incidents, a common theme emerges. The most significant computer crimes were not isolated hacks but complex operations combining technical skill, strategic planning, and an understanding of human and organisational behaviour. Whether motivated by money, ideology, or geopolitical goals, these attacks reshaped how security is perceived and implemented. They forced industries to adopt new defensive models, governments to develop cyber strategies, and societies to acknowledge that digital systems are now inseparable from physical reality.
Computer crime has evolved from nuisance to existential risk, capable of disrupting healthcare, energy, finance, and national security. The lessons learned from these top crimes continue to influence software development, incident response, and international policy. As systems grow more interconnected, the potential impact of future attacks will only increase, making the understanding of past incidents not merely historical interest but essential preparation for what lies ahead.