Malware attacks are on the rise across the US, but some cities are more susceptible than others, according to a recent report from Enigma Software Group (ESG). In 2016, Tampa, Orlando, and St. Louis each had malware infection rates per capita more than five times the national average–the highest in the US, the report found.

Those same three cities were also at the top of the list of highest infection rates in 2015.

“There could be a number of factors including the demographics of the area, how widespread PC usage is (versus Mac or mobile devices), we’ve even seen weather play a role in infections from time to time,” said ESG spokesperson Ryan Gerding in a press release. “The important thing is that people in these cities, and everywhere else for that matter, need to always remain vigilant against malware, spyware, and other nefarious online activity.”

ESG compiled malware detection data from its SpyHunter anti-spyware software in the 100 largest cities in the US in all of 2016.

SEE: Rise of the ‘accidental’ cybersecurity professional

Enterprises should be on the lookout for ransomware attacks in particular: Nearly half of businesses report that they were the subject of a cyber-ransom campaign in 2016, according to a recent Radware report. These attacks cost organizations an estimated $1 billion in 2016, ZDNet reported.

Ransomware attacks will continue to rise in 2017, experts predict, and will continue to target business users. Cyber attacks via cloud-based applications and spam are on the rise this year as well, according to a recent Cisco security report.

Here are the cities with the highest rates of malware infections in 2016.

1. Tampa, Florida

Tampa experienced malware attacks at rates 540% higher than the national average. The city is home to three of Florida’s top 10 public companies: Tech Data, Jabil Circuit, and WellCare Health Plans.

2. Orlando, Florida

Orlando reached number two on the list of highest malware infections per capita in 2016, at rates 525% higher than the national average. Major companies located in Orlando include JetBlue, AAA, and Lockheed Martin.

3. St. Louis, Missouri

St. Louis rounds out the top three on the list, with malware rates 520% higher than the national average. World Wide Technology, Graybar, and SuddenLink Communications are all based in St. Louis.

4. Denver, Colorado

At number four on the list, Denver’s malware rates were 407% higher than the national average–more than 100% lower than St. Louis’s rates. Denver is home to Arrow Electronics, DISH Network, and Frontier Airlines.

5. Atlanta, Georgia

Atlanta’s per capita malware rates were 370% above the national average in 2016. Mercedes-Benz, Yik Yak, and MailChimp are headquartered in Atlanta.

6. Newark, New Jersey

At number six, Newark experienced malware attacks at rates 322% higher than the national average. Audible Inc., IDT Corporation, and Prudential Financial are based in Newark.

7. Madison, Wisconsin

Madison, home to EatStreet, Full Compass Systems, and Alliant Energy, saw malware infections at 272% higher than the national average.

8. Washington, DC

The nation’s capital was the eighth highest hit with malware attacks in 2016, at rates 242% higher than the national average. The headquarters of Marriott Hotels & Resorts and The Data Incubator are located in Washington, DC.

9. Cleveland, Ohio

Cleveland, home to the Sherwin-Williams Company and Goodyear, had malware attacks 213% higher than the national average.

10. Cincinnati, Ohio

Rounding out the top 10 was Cincinnati, with malware rates 194% higher than the national average. Procter & Gamble Co., Mitsubishi, and GE Aviation are headquartered in Cincinnati.