Cybersecurity mistakes businesses make are rarely dramatic. They don’t usually start with a shadowy hacker in a hoodie cracking some impossible code. More often, they start with an untrained employee clicking a phishing link, a forgotten API endpoint left open, or a vendor with weak access controls sitting inside your network.
That’s the uncomfortable truth: most cyberattacks don’t beat your defenses, they walk right through gaps you didn’t know existed.
This article covers five of the most common, and costly cybersecurity mistakes companies make across employee training, supply chain visibility, API security, remote access, and backup processes. More importantly, it covers what you can actually do to fix them.
Five Top Cybersecurity Mistakes
1. Neglecting Effective Employee Training
Human error is the single biggest driver of data breaches. According to the 2025 Verizon Data Breach Investigations Report, 60% of breaches involve a human element, whether that’s falling for a scam, mishandling credentials, or making a simple mistake under pressure. IBM’s research puts that figure even higher, at 74%.
What makes this worse: just 8% of employees account for 80% of all security incidents, according to a 2025 Mimecast study. A small group of untrained, or undertrained, people can do enormous damage.
For small and medium-sized businesses (SMBs), the picture is even more concerning. Only 39% of SMBs provide regular cybersecurity training to their staff (Nevada IT Solutions, 2024). That means most small businesses are running on the assumption that their employees will just “know better”, and that assumption is expensive. The average cyberattack on an SMB costs $200,000, enough to put many of them out of business permanently.
“The reason human error dominates breach statistics is straightforward. When attackers use stolen credentials, nothing looks wrong.” — BreachSense, 2026
Security awareness training that actually works looks different from the checkbox compliance exercise most companies run once a year. To improve the effectiveness of your training program:
- Run short, frequent sessions (monthly or bi-weekly) rather than a single annual module. Retention drops sharply after a one-off event.
- Use phishing simulations and gamified exercises to make threats feel real before employees face them in the wild.
- Track and measure results. Organizations with comprehensive training programs can reduce phishing susceptibility by up to 86% compared to their starting baseline (Brightside AI, 2025).
- Make it role-specific. A finance team member faces different threats than an engineer. Generic training misses both.
The bottom line on security awareness training: it’s not a “nice to have.” It’s your cheapest and most scalable line of defense against the attack vectors that cause the majority of breaches.
2. Poor Supply Chain Visibility
Your cybersecurity posture is only as strong as the weakest link in your supply chain, and that link is often someone else’s problem entirely.
Supply chain attacks have surged dramatically. According to the 2025 Verizon DBIR, 30% of breaches involved third-party vendors, twice the rate from the previous year. Meanwhile, Cyble data shows software supply chain attacks hit a record high in October 2025, running at more than twice the monthly rate seen in early 2024.
The financial stakes are real. Supply chain breaches add approximately $227,000 to the average breach cost (IBM, 2025), and cyberattacks targeting the software supply chain are projected to cost the global economy $80.6 billion annually by 2026 (Indusface).
| Supply Chain Attack Stat | Source |
|---|---|
| 30% of breaches involved third-party vendors in 2025 | Verizon DBIR 2025 |
| 98% of businesses are concerned about supply chain compromise | Security Magazine |
| 41% of SMBs reported being affected by a supply chain attack in 2023 | Nevada IT Solutions |
| Supply chain breaches add ~$227K to average breach cost | IBM, 2025 |
The 2024 Change Healthcare attack is a hard example of this. A ransomware group compromised 100 million patient records and disrupted healthcare operations nationwide, not by breaking through Change Healthcare’s own firewall, but by exploiting a credential that lacked multi-factor authentication (MFA) on a remote server. The company paid a $22 million ransom and lost an estimated $2.3 billion for the year.
To reduce your exposure to third-party access risks:
- Map your entire supply chain, including deep-tier vendors and the third-party libraries your software depends on. You can’t protect what you can’t see.
- Create data-sharing agreements that hold vendors to defined security standards — not just your first-tier partners, but anyone with access to your systems.
- Run periodic security audits on suppliers. Compliance today doesn’t guarantee security tomorrow.
- Limit third-party access to the minimum scope required. Treat vendor access the way you treat privileged internal access.
3. Underestimating API Vulnerabilities
Application programming interfaces (APIs) are the connective tissue of modern software. Every time your app pulls data from another service, authenticates a user, or sends a transaction, it’s using an API. That makes them incredibly powerful, and an increasingly attractive target.
API data breaches rose 80% year-over-year in 2024, with the volume of records compromised growing 214% (FireTail, 2024). The Akamai 2024 API Security Impact Study found that 84% of security professionals experienced an API security incident in the past year. Yet only 27% of organizations have a full API inventory and know which of their APIs expose sensitive data, down from 40% the year before.
That gap between exposure and awareness is where attacks happen.
“Current data indicates that the average API breach leads to at least 10 times more leaked data than the average security breach.” — Gartner, May 2024
Real-world examples from 2024 illustrate the scale: a Trello API breach exposed 15 million users; a Dell API vulnerability compromised 49 million customer records; NHS patient data for nearly one million people was exposed through weak API token management. These weren’t sophisticated zero-day exploits. Most came down to missing authentication controls and poor access management, issues covered directly in the OWASP Top 10 API Security Risks.
To get a genuine grip on API security:
- Study the OWASP Top 10 API Security Risks and ensure your development team addresses each one systematically.
- Deploy API gateways to monitor, manage, and control traffic between clients and back-end services.
- Maintain continuous API monitoring and logging for all calls. Suspicious activity is detectable, if you’re looking.
- Conduct regular API-specific security audits, not just general vulnerability scans. APIs need their own testing discipline.
- Never hardcode API keys into source code or leave them exposed in public repositories.
4. Remote Access Security
Remote work permanently expanded the attack surface of most organizations, yet security policies haven’t kept pace with that shift.
The risks are layered. Employees connect through home networks with unknown security configurations, use personal devices that IT has no visibility into, and use collaboration platforms like Slack, Asana, and Microsoft Teams with default settings that were never designed with security-first assumptions in mind.
More than 56% of IT leaders believe remote work increases the likelihood of breaches caused by human error (IS Partners, 2024). And 72% of business owners are concerned about future cybersecurity risks from hybrid and remote work environments (Viking Cloud, 2025).
Remote desktop protocol (RDP) access, VPN configurations, and unsecured Wi-Fi remain the three most common technical failure points. The Change Healthcare breach — the most disruptive cyberattack on U.S. critical infrastructure to date, could have been entirely prevented by enabling MFA on a single remote access server.
| Common Remote Access Risk | What It Enables |
|---|---|
| No MFA on VPN or RDP | Credential-based access without a second check |
| Default settings on Teams/Slack | External parties can message internal staff |
| Unsecured home Wi-Fi | Network interception |
| Personal device use without endpoint protection | Malware entry point |
| Flat network access for remote users | Lateral movement after initial compromise |
To improve remote access security across your organization:
- Mandate multi-factor authentication (MFA) for every remote login, VPN, RDP, and all collaboration platforms. No exceptions.
- Audit default configurations on team tools. In Microsoft Teams, disable external tenant communication where it isn’t needed. In Slack, restrict external sharing permissions.
- Enforce endpoint protection on all devices accessing company systems, whether company-issued or personal.
- Segment your network so a compromised remote connection doesn’t give lateral access to the whole environment.
- Run regular security audits on VPN configurations and remote access policies as your workforce and tools evolve.
5. Inadequate Backup and Recovery Processes
When everything else fails, a solid backup and disaster recovery plan is what keeps you in business. Companies that skip this step don’t just face a security incident, they face an existential one.
Ransomware attacks hit 59% of organizations in 2024 (Sophos). The average ransom payment jumped from $400,000 in 2023 to $2 million in 2024. And paying up doesn’t guarantee resolution: in 2024, 84% of victims paid ransoms but only 47% got their data back uncorrupted (Spin.AI).
Perhaps most troubling: 78% of organizations attacked in 2023 were breached again in 2024, with 63% of repeat victims asked to pay even higher ransoms the second time. Without a recovery plan, you’re not just vulnerable to one attack, you become a repeat target.
“Without adequate backups, you might feel compelled to pay ransoms in ransomware attacks to regain access to important data and systems.”
Inadequate backup processes take several forms, no backup strategy at all, backups stored on the same network as production systems (making them just as vulnerable), cloud backups without isolation, and untested backups that fail when they’re actually needed. Research found that 58% of data backups fail when tested in real recovery scenarios.
The 3-2-1 backup rule exists for a reason: maintain 3 copies of your data, stored on at least 2 different types of media, with 1 copy kept off-site. Cloud-based solutions can handle the redundancy and geographic isolation components effectively.
To build a backup and recovery process that actually protects your business:
- Develop a documented disaster recovery plan (DRP) with step-by-step procedures for restoring systems after a cyberattack. Test it quarterly, not just annually.
- Follow the 3-2-1 backup rule and ensure at least one copy is air-gapped or isolated from your production network environment.
- Use cloud-based solutions for redundancy, geographic flexibility, and rapid recovery of services.
- Test your backups regularly under realistic conditions. A backup that’s never been restored is a backup you can’t trust.
- Set recovery time objectives (RTOs) and recovery point objectives (RPOs) so you know exactly how fast you need to recover and how much data loss is acceptable.
In Summary
The five cybersecurity mistakes businesses make most often, neglecting employee training, poor supply chain visibility, underestimating API vulnerabilities, weak remote access security, and inadequate backup and recovery processes, share a common thread: they’re all fixable.
None of them require unlimited budgets. All of them require deliberate action.
Security awareness training reduces human error. Supply chain audits close third-party gaps. API security programs using the OWASP Top 10 API Security Risks address the fastest-growing attack surface in modern software. Multi-factor authentication on remote access blocks a massive class of credential-based attacks. And a tested disaster recovery plan means that when ransomware hits, not if you have an exit that doesn’t involve paying a ransom.
For many businesses, especially SMBs without a dedicated security team, partnering with a Managed Security Services Provider (MSSP) is the most practical way to close multiple gaps simultaneously. MSSPs bring continuous monitoring, Managed Detection and Response (MDR), Endpoint Detection and Response (EDR), incident readiness programs, and security posture assessments to the table, capabilities that are difficult to build internally at any scale.
