The human factor in cyber security: how employees are your biggest cyber security threat

Why employees are the weakest link in cyber security

Originally published 15 March 2023 – updated July 2025

Even with advanced firewalls and encryption, many organisations overlook a critical vulnerability: their own staff. Research from IBM’s 2022 Cost of a Data Breach report shows that human error is the leading cause of data breaches, with phishing attacks alone causing significant financial losses globally. This highlights that employees are often a conduit for the biggest cyber security threats, unintentionally creating openings that cybercriminals can exploit.

How human errors contribute to the biggest cyber security threats

A 2022 study by Kaspersky found that staff-related mistakes are the second most common cause of serious security breaches, just behind malware, with nearly half of all incidents involved careless or uninformed employees. These errors can take many forms, such as; falling for phishing emails; sharing sensitive data via unsecured devices; misplacing company equipment; using weak or repeated passwords; or neglecting to apply crucial security updates. Each of these seemingly small actions can create a gateway for the biggest cyber security threats to penetrate an organisation.

The wider impact of human error

The consequences of such breaches extend far beyond financial loss, with mistakes made by employees able to damage an organisation’s reputation, erode customer trust, and even result in legal or regulatory penalties. With cybercriminals increasingly using social engineering tactics, employees may be manipulated into revealing confidential information or granting access to secure systems, reinforcing the idea that human factors remain one of the biggest cyber security threats facing organisations today.

Strengthening your organisation's cyber defences

Mitigating these risks is as much about culture as it is about technology, so ensuring regular training for staff allows them to understand the latest threats and adopt safe practices, whilst clear policies on device and data use provide a consistent framework. 

Multi-factor authentication adds an extra layer of security, and routine audits help detect unusual activity before it escalates. Encouraging employees to report suspicious behaviour without fear of reprisal transforms potential vulnerabilities into proactive guardians of the business, significantly reducing the likelihood that human error becomes the source of the biggest cyber security threats.

By fostering a security-conscious culture and combining it with technical safeguards, organisations can turn employees from a potential risk into a powerful line of defence against cybercrime.