(Radio Iowa) — If you paid a parking ticket in Sioux City or paid a city utility bill in late summer, your personal data may be at risk. City Attorney Nicole Dubois says a piece of malicious code was inserted into the website for paying bills to the City of Sioux City and electronic transactions between August 26th and September 18th may have been affected.

“Addresses, names, credit card information,” she says. “But please keep in mind Social Security numbers, dates of birth — that information was not compromised, so it’s limited to the credit card and address information.” The website that was hacked is managed and operated by a third-party vendor. Sioux City officials say more than 35-hundred accounts are potentially affected by the data breach.

Dubois says all affected individuals will soon receive a letter from the City of Sioux City with credit monitoring information. “But in the meantime before they receive those letters, we would encourage anyone…to pull copies of their credit reports,” Dubois says. “They can get contact information there.”

The City of Sioux City had already switched to a different vendor’s website for paying bills electronically when the data breach was reported by the previous vendor.