But even though the spending increased, cyber security-related expenditure still accounted for only 2% of total IT expenditure, Canalys said in a statement.
The firm said it estimated that by 2020, global cyber security expenditure would rise above US$42 billion.
"Over the next two years, the transition in cyber security deployment models will accelerate," said Canalys principal analyst Matthew Ball.
The company said its data showed that last year, traditional hardware and software deployment constituted 82% of the cyber security market and this was expected to fall to 70% by 2020.
The remaining expenditure in 2018 (18%) was spent on deployment of virtual appliances and agents, buying through public cloud marketplaces and subscriptions to cyber security as a service.
"Vendors will have to establish a diverse range of business models to support this transition, as different products suit different types of deployments," said Ball.
"The key challenge to date for many has been making the new models more channel-centric, and integrating them with existing partner programs, especially customer transactions via cloud marketplaces."
"This has recently been addressed by some cloud marketplaces, allowing partners to offer customised deals and pricing direct to customers, while tracking deal registration and rebates."
Canalys research analyst Ketaki Borade said leading cyber security vendors had embraced new deployment models, and were moving their businesses to more subscription-based revenue and increasing transactions via cloud marketplaces.
Canalys said in the final quarter of 2018, Cisco remained the overall worldwide market leader, increasing its share from the previous year to just under 10%. Palo Alto Networks grew faster but remained in second place with 7%. Check Point, Fortinet, IBM and Symantec each had 6% market share in Q4. Overall, the top 10 cyber security vendors collectively represented 53% of shipments during this period, with the next 20 accounting for 21%.
Borade said: "Cisco, Palo Alto Networks, Barracuda and Check Point are also the top cyber security vendors on the leading public cloud marketplace, AWS Marketplace, selling their virtual offerings on a per hour and annual basis.
"This is still a small part of their overall business, but is the fastest growing area. Barracuda Networks, Trend Micro and F5 Networks also have a strong presence on cloud marketplaces, highlighting their early move to adopt new deployment models."
Charts: courtesy Canalys