As network-layer denial-of-service (DDoS) attack trends continue, Akamai Technologies’ recent research showed a significant uptick in application-layer attacks.

Despite layer 7 DDoS being more expensive and difficult to execute, researchers found the number and scale of this type of attack increased significantly. “DDoS extortion, application assaults, and targeted attacks against internet-facing infrastructure continue to pose a threat to organizations across all industries globally,” the Akamai security research team wrote in a blog post. 

In June, Google Cloud claimed it blocked the largest layer 7 DDoS reported to date, which is at least larger than the previously reported record. The attackers used HTTPS-based requests that peaked at 46 million requests per second. 

Akamai researchers warn these type of attacks won’t be anomalies for long, and they also found the most frequent attack vector for DDoS has been HTTPS flood accounting for 35% of total attacks they monitored between the first quarter of 2021 to the first quarter of this year.

Plus, the DDoS attacks are evolving from single-vector to multi-vector. All those changes are largely due to the internet behavior evolution, researchers noted.

“Layer 7 DDoS attacks are difficult to detect because it can be difficult to differentiate legitimate human behavior from bot activity on these web-facing applications,” they wrote, adding the detection and mitigation are more “hands-on-keyboard.”

Additionally, the potential impact of those attacks is more notable. The research found that DDoS attackers now not only seek financial gains, they also look to damage the reputation of the victimized businesses, similar to how ransomware groups operate.

“The targets of DDoS attackers are specifically chosen and executed against,” the team wrote. “This isn’t to say compensation isn’t a factor. It simply isn’t the primary motivation. These attacks are more personal; sometimes, they’re even politically motivated.”

Amid the nature of the business, the financial service industry is still suffering the most constant barrage of DDoS attacks, Akamai research showed.

The vendor’s wealth management customers have been experiencing layer 7 DDoS extortion attacks since November last year.

“The high financial stakes and abundance of sensitive data and customer personally identifiable information they hold are highly enticing to an attacker,” Akamai researchers noted.