Photos: AP

’Tis the season to be jolly -- unless, that is, your computer gets infected with malware.

Such infections spike every year during the holidays, thanks to the increase in online shoppers -- and the concomitant increase in the grinches who try to take advantage of them.

The Thanksgiving weekend provided a hint of how bad it’s going to be this season. Computer security company Enigma Software Group examined malware infections reported via its SpyHunter software and compared the data to the previous month. Its conclusion: A 123% jump in malware infections during the four-day shopping bonanza.

You might think that malware infections would be pretty evenly distributed around the country, but that’s not the case. Some places get hit much harder than others. Below are the 30 U.S. cities with the highest malware-infection increases during the Thanksgiving weekend, according to Enigma.

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1. Charlotte, N.C.

316.29%

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2. Detroit

275.78%

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3. New York City

237.93%

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4. Salt Lake City

212.77%

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5. Sacramento

210.22%

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6. Grand Rapids, Mich.

203.31%

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7. Austin

190.95%

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8. St. Louis

179.04%

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9. Columbus, Ohio

169.63%

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10. Baltimore

167.54%

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11. Kansas City

163.32%

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12. Denver

156.42%

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13. Chicago

155.34%

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14. Boston

155.06%

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15. Cleveland

146.57%

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16. Miami

133.11%

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17. Louisville

132.27%

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18. Little Rock

129.17%

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19. San Diego

123.60%

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20. Phoenix

121.27%

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21. Milwaukee

114.29%

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22. Washington, D.C.

114.22%

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23. Tampa

112.34%

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24. Pittsburgh

111.71%

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25. Dallas

109.48%

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26. Portland

107.76%

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27. Houston

99.63%

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28. Buffalo

93.42%

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29. Las Vegas

88.11%

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30. San Antonio

87.77%

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More

For more information on the data, as well as tips on avoiding malware infection, go to Enigma's website.