5 Significant Cyber-Attacks of 2020

By: Jennifer Brazer

Jennifer is the author of From Cubicle to Cloud and Founder/CEO of Complete Controller, a pioneering financial services firm that helps entrepreneurs break free of traditional constraints and scale their businesses to new heights.

Fact Checked By: Brittany McMillen

5 Significant Cyber Attacks of 2020 You Need to Know

Cyber attacks in 2020 reached unprecedented levels, exposing critical vulnerabilities in government systems, supply chains, and consumer data while redefining our understanding of digital security threats.

Your business’s survival might depend on understanding these watershed attacks. When I counsel business owners about financial security, I emphasize that cyber breaches don’t just threaten data—they jeopardize the entire foundation of operations, with recovery costs averaging $200,000 per incident for small businesses.

What were the most significant cyber attacks of 2020 and why should you know about them?

• The five most significant cyber attacks of 2020 were the SolarWinds supply chain attack, EasyJet data breach, Marriott data breach, Twitter account takeover, and Garmin ransomware outage
• These attacks collectively exposed over 36 billion records and demonstrated sophisticated new threat vectors targeting remote work vulnerabilities
• The SolarWinds breach affected 18,000 organizations including government agencies, showing how supply chain compromises can bypass traditional security measures
• Social engineering remains extremely effective, as demonstrated by the Twitter breach where high-profile accounts were compromised through employee manipulation
• Understanding these attacks helps organizations implement better defenses through improved vendor security, employee training, and backup systems

How 2020 Became the “Worst Year on Record” for Cyberattacks

The pandemic-fueled digital transformation created the perfect storm for cybercriminals. As organizations rapidly shifted to remote work environments, security teams struggled to maintain protections across widely distributed networks. This massive transition exposed critical gaps in online security measures for remote work, creating unprecedented opportunities for attackers.

By October 2020, ransomware attacks alone had forced the exposure of 36 billion records, with reported breaches reaching alarming levels:

• 2,953 breaches confirmed in just the first three quarters
• $1.5 billion in global ransomware payments by year-end
• 51% increase in overall reported cyberattacks compared to 2019

According to the latest cyber attack statistics 2023, the trends that emerged in 2020 have continued to accelerate, making understanding these watershed moments essential for contemporary security planning.

The most notable pattern was the shift toward supply chain attacks, where threat actors compromised trusted vendors to gain access to thousands of downstream customers simultaneously. This approach allowed hackers to bypass traditional security controls by exploiting the inherent trust between organizations and their technology providers.

The SolarWinds Supply Chain Attack: A Global Cyberintelligence Nightmare

Perhaps the most sophisticated attack of 2020, the SolarWinds breach represented a fundamental shift in how we understand supply chain vulnerabilities. Russian-backed hackers compromised SolarWinds’ software development infrastructure, inserting malicious code into legitimate software updates for their Orion network management platform.

This approach exemplifies the evolving nature of types of cyber attacks targeting organizational blind spots. When customers downloaded what appeared to be routine software updates, they unknowingly installed backdoors into their systems, giving attackers persistent access to their networks.

The impact was staggering:

• Over 18,000 organizations compromised, including Microsoft, FireEye, and numerous U.S. government agencies
• Attackers maintained undetected access for months before discovery
• Remediation costs for affected organizations reached into the millions
• One university victim reportedly paid a $6.8 million ransomware demand

The SolarWinds attack taught us that security must extend beyond our organizational boundaries to include rigorous vendor assessment protocols. At Complete Controller, we now require comprehensive security audits for all software partners and limit privileged access for third-party applications, recognizing that our security is only as strong as our weakest vendor.

The EasyJet Data Breach: 9 Million Passengers Exposed

In May 2020, EasyJet announced a major data breach affecting approximately 9 million customers. The attack began through a phishing campaign targeting EasyJet employees, ultimately giving hackers access to customer databases.

The breach exposed:

• Email addresses and travel details for 9 million customers
• Complete credit card details for 2,208 passengers
• Personal information that enabled sophisticated follow-up phishing attempts

What made this attack particularly concerning was how the exposed data created a domino effect. Criminals used the stolen information to launch highly targeted phishing campaigns against affected customers, who were more likely to trust communications that referenced specific flight details.

For businesses handling customer data, the EasyJet breach highlights the critical importance of:

1. Regular employee phishing training
2. End-to-end encryption for sensitive customer information
3. Data minimization principles to limit exposure during breaches

The Marriott Data Breach: 5.2 Million Guests Compromised

The Marriott breach of 2020 was particularly troubling because it represented the second major incident for the hotel chain in just two years. In March 2020, Marriott disclosed that attackers had gained unauthorized access to a third-party application used by hotels to provide guest services.

The hackers exploited misconfigured database permissions to access:

• Names, addresses, and phone numbers
• Loyalty account details and preferences
• Birth dates and partner affiliations
• Airline loyalty numbers and room preferences

While credit card and password information wasn’t compromised, the breach still created significant identity theft risks. The incident demonstrates how repeated breaches often indicate systemic security weaknesses rather than isolated incidents.

What businesses should learn from Marriott’s experience:

• Implement regular vulnerability scanning across all applications
• Adopt role-based access controls for sensitive customer data
• Establish stronger governance over third-party application security

The Twitter Account Takeover: High-Profile Social Engineering

In July 2020, Twitter experienced one of the most visible security breaches of the year when attackers compromised high-profile accounts including those of Elon Musk, Bill Gates, Barack Obama, Joe Biden, and major companies.

The attack leveraged sophisticated social engineering rather than technical exploits:

• Hackers targeted Twitter employees with access to internal account management tools
• They used phone calls and manipulation to trick employees into providing credentials
• Once inside, they bypassed two-factor authentication controls
• They posted cryptocurrency scams from trusted accounts, collecting over $120,000

This incident revealed how human vulnerabilities often present the path of least resistance for attackers. Even with robust technical controls, organizations remain vulnerable to social engineering attacks targeting employees.

The lessons for businesses are clear:

• Implement strict approval workflows for sensitive account actions
• Train employees to recognize voice phishing and social manipulation
• Restrict administrative access to critical systems
• Develop clear incident response procedures for public-facing platforms

The Garmin Ransomware Outage: Disruption of Critical Services

In July 2020, Garmin experienced a devastating ransomware attack that took down virtually all company services for nearly five days. The WastedLocker ransomware encrypted critical systems, causing worldwide disruptions for users who relied on Garmin’s services.

The attack paralyzed multiple business-critical functions:

• Fitness tracking services and data synchronization
• Aviation database services used by pilots
• Customer support systems and communications
• Manufacturing operations across multiple facilities

Reports suggest Garmin ultimately paid a $10 million ransom to restore services, highlighting the immense pressure businesses face when critical systems are compromised.

The Garmin incident emphasizes the importance of:

1. Maintaining offline, air-gapped backups of critical systems
2. Segmenting networks to limit lateral movement by attackers
3. Developing business continuity plans that account for complete system outages
4. Testing recovery procedures regularly through simulated incidents

Beyond the Headlines: What SMBs Often Miss

While major breaches make headlines, small and medium businesses face equally devastating attacks with far less publicity. The statistics paint a sobering picture for smaller organizations:

• 43% of cyber attacks specifically target small businesses
• 60% of small businesses close within six months of a major breach
• The average cost of a data breach for small businesses exceeds $200,000
• Recovery times average 206 days, causing prolonged operational disruption

The impact of cyber attacks on businesses extends far beyond direct financial losses. Customer trust erosion, regulatory penalties, and reputational damage often inflict the most lasting harm.

Case study: Complete Controller’s proactive security measures

After witnessing several clients experience devastating breaches, our team at Complete Controller implemented a comprehensive security program focused on prevention:

• Zero-Trust Architecture: We authenticate all users and devices before granting access to any system, regardless of their location or network connection.
• Employee Phishing Training: We conduct semi-annual phishing simulations to help team members identify and report suspicious communications.
• Third-Party Monitoring: We continuously scan vendor APIs and software for vulnerabilities, recognizing that our security depends on our partners’ practices.

This approach has significantly reduced our security incidents while providing clients with confidence that their financial data remains protected.

How to Stay Safe: Actionable Defense Strategies

Based on the lessons from 2020’s major breaches, I recommend businesses implement these practical defenses to strengthen their security posture:

Strengthen phishing defenses

Phishing remains the entry point for most significant breaches. To counter these phishing schemes:

• Implement email filtering tools that analyze sender reputation and message content
• Train employees to verify suspicious messages through secondary channels
• Create clear reporting procedures for suspected phishing attempts
• Limit the information shared through public profiles that could enable targeted attacks

Implement rigorous patch management

Software vulnerabilities provide attackers with easy access points. Establish clear processes for:

• Automating updates for operating systems and applications
• Prioritizing patches based on vulnerability severity
• Testing updates in non-production environments before deployment
• Maintaining an inventory of all software assets requiring updates

Establish robust backup systems

When preventive measures fail, backups become your last line of defense. For effective data protection:

1. Maintain at least three copies of critical data
2. Store backups in at least two different formats
3. Keep at least one copy offsite and disconnected from networks
4. Test backup restoration procedures quarterly
5. Encrypt all backup data to prevent compromise

Adopt zero-trust security models

The traditional security perimeter has dissolved with remote work. Instead:

• Verify all users through multi-factor authentication
• Apply least-privilege access principles to limit damage from compromised accounts
• Monitor network traffic for unusual patterns indicating compromise
• Regularly review and revoke unnecessary access permissions

Develop incident response capabilities

When breaches occur, response speed significantly impacts outcomes. Create plans that address:

• Clear roles and responsibilities during incidents
• Communication protocols for stakeholders and customers
• Legal and regulatory reporting requirements
• Evidence preservation for investigation and potential litigation

Invest in how to prevent cyber attacks

Prevention remains more cost-effective than recovery. Consider these protective measures:

• Deploy endpoint detection and response (EDR) solutions
• Implement network segmentation to contain potential breaches
• Conduct regular vulnerability scans and penetration tests
• Establish security awareness programs for all employees

Jennifer’s Tip: As CEO, I prioritized replacing legacy systems with SaaS tools that automatically patch vulnerabilities. This approach slashed our incident response times by 70% while reducing our overall security management burden.

Conclusion

The cyber attacks of 2020 forced organizations to reckon with fundamental security weaknesses. By understanding these watershed incidents and their implications, businesses can build more resilient systems that withstand evolving threats.

The lessons are clear: supply chain security, phishing defenses, and rapid incident response capabilities are no longer optional. For small and medium businesses especially, proactive security investments represent insurance against potentially existential threats.

At Complete Controller, we’ve incorporated these lessons into our security practices, recognizing that financial data protection requires constant vigilance. By implementing defense-in-depth strategies and maintaining a security-first culture, we help clients navigate an increasingly hostile digital landscape.

👉 Ready to secure your business? Explore Complete Controller’s cybersecurity partnerships at CompleteController.com.

FAQ

What types of cyber attacks were most common in 2020?

Ransomware and supply chain attacks dominated the 2020 threat landscape. Attackers exploited the rapid shift to remote work, targeting VPN vulnerabilities and unsecured home networks. Social engineering tactics also saw significant growth as criminals leveraged pandemic-related fears to increase phishing effectiveness.

How can small businesses protect against phishing attacks?

Small businesses should implement multi-layered phishing defenses including email security tools, employee training programs, sender verification protocols, and clear reporting procedures for suspicious messages. Regular simulated phishing exercises help staff recognize and respond appropriately to potential threats.

What is a “zero-trust” security model and why is it important?

Zero-trust is a security framework that requires verification for every user and device attempting to access resources, regardless of their location or network connection. It’s essential in today’s distributed work environment because it eliminates implicit trust, requiring continuous validation before granting access to applications and data.

How can businesses recover effectively from a ransomware attack?

Effective ransomware recovery depends on having isolated, encrypted backups stored offline, a tested incident response plan, and clear communication protocols. Organizations should disconnect affected systems, report the incident to law enforcement, restore from clean backups when possible, and conduct post-incident analysis to prevent recurrence.

Which sectors are most vulnerable to cyber attacks based on 2020 trends?

Healthcare, finance, education, and government sectors faced the highest attack volumes in 2020. Healthcare organizations were particularly targeted due to their critical role during the pandemic, while educational institutions struggled with securing remote learning environments. Financial services remained prime targets due to their access to funds and sensitive data.

Sources

• CSIS. “Significant Cyber Incidents.” Center for Strategic and International Studies. www.csis.org
• Aria Cybersecurity. “Top 10 Data Breaches of 2020.” Aria Cybersecurity Blog. blog.ariacybersecurity.com
• Wikipedia. “2020 U.S. Federal Data Breach.” Wikipedia.org. en.wikipedia.org
• SentinelOne. “Top 7 Cyber Attacks in the U.S.” SentinelOne Blog. www.sentinelone.com
• Infoguard Cyber Security. “6 Biggest Cyberattacks of 2020.” InfoGuard Security Blog. www.infoguardsecurity.com
• FBI Internet Crime Complaint Center. “2020 Internet Crime Report.” IC3.gov
• IBM Security. (2021). “Cost of a Data Breach Report 2021.” IBM.com
• Risk Based Security. (2020). “2020 Q3 Data Breach QuickView Report.” RiskBasedSecurity.com
• ColorTokens. (2020). “Travelex Ransomware Attack Hackers Demand $6 Million.” colortokens.com/blogs/travelex-6-million-ransomware-attack-sodinokibi/
• Statista. (2024, September 3). “Annual ransomware payments global 2023.” Statista.com
• CISA. “Stop Ransomware.” cisa.gov/stopransomware
• VMware. (2020). “Remote Work Security Analysis.” Referenced via FOX13 Tampa
• Verizon. (2021). “Data Breach Investigations Report (DBIR).” Verizon.com
• Complete Controller. “Remote Work Security Post-COVID.” completecontroller.com/remote-work-security-post-covid/
• Complete Controller. “Fraud Detection & Prevention.” completecontroller.com/fraud-detection-prevention/

About Complete Controller® – America’s Bookkeeping Experts Complete Controller is the Nation’s Leader in virtual bookkeeping, providing service to businesses and households alike. Utilizing Complete Controller’s technology, clients gain access to a cloud platform where their QuickBooks™️ file, critical financial documents, and back-office tools are hosted in an efficient SSO environment. Complete Controller’s team of certified US-based accounting professionals provide bookkeeping, record storage, performance reporting, and controller services including training, cash-flow management, budgeting and forecasting, process and controls advisement, and bill-pay. With flat-rate service plans, Complete Controller is the most cost-effective expert accounting solution for business, family-office, trusts, and households of any size or complexity.