Researchers at Barracuda have found that smaller companies tend to receive a higher rate of phishing attacks spread across the organization, according to a report looking at the phishing attack surfaces of companies of different sizes.

This is likely due to the smaller number of potential targets and the higher level of access possessed by each employee. At larger organizations, spear phishing attacks generally focus on specific, high-value targets, such as executives or employees with access to financial decisions.

“Smaller companies tend to have flatter organizational structures with easier access to names or contact details,” Barracuda explains. “This could mean that attackers can target a wide range of employees. Due to their smaller size, they are also likely to have more people with privileged access to data and systems. There are fewer degrees of separation between employees, enabling attackers to move laterally quickly. As a result, inbound attack emails are more evenly distributed across the business and could target the intern as well as the CEO.”

Phishing remains a top threat for large organizations as well. Barracuda found that attacks against large companies often involve lateral phishing, in which threat actors use compromised accounts to send phishing emails to other accounts within the organization.

“Just under half (42%) of the targeted email attack detections in the largest companies involved lateral phishing, compared to only 2% for the smallest organizations,” the researchers write. “This internal attack vector is a major risk for large businesses. The prevalence of account compromises among larger businesses may reflect the fact that credentials for many companies are likely already available for purchase on the dark web, making lateral phishing a straightforward attack.”