CNN  — 

Spikes in car thefts of certain Hyundai and Kia models, a trend that began in the American midwest and was spread by how-to videos on social media, has reached America’s biggest city.

About 100 of these particularly vulnerable Hyundai and Kia vehicles were stolen in the month of December alone in New York City, according to New York City Police Commissioner Keechant Sewell. Thefts started rising around September of last year.

“Before then we were averaging probably 10 to 12 thefts of these cars a month,” she said in a press conference Thursday, “and by December we were up to about 100.”

The vehicles in question, 2015-2019 Hyundai and Kia models, such as the Hyundai Santa Fe and Tucson and the Kia Forte and Sportage, when equipped with turn-key ignitions — as opposed to cars that only require a button to be pushed to start — are roughly twice as likely to be stolen as other vehicles of a similar age. Many of these vehicles lack some of the basic auto theft prevention technology included in most other vehicles, even in those years, according to the Highway Loss Data Institute, an industry group that tracks insurance statistics.

Joy rides on Tik Tok

These models became the subject of a viral social media trend in which thieves filmed themselves and others stealing Hyundai and Kia vehicles and taking them for a drive. In some parts of the country, the problem became so bad that some insurance companies refused to write new policies on these Hyundai and Kia models in places where the thefts had become extremely common.

The models in question don’t have electronic immobilizers, which rely on a computer chip in the car and another in the key that communicate to confirm that the key belongs with that vehicle. Without the right key, an immobilizer should do just that — stop the car from moving.

The New York thefts first began to be noticed in The Bronx, the commissioner said, but soon were also happening in other parts of the city.

Most of the SUVs and cars are being found abandoned later and seem to have been simply for “joy-riding,” Sewell said, but there is also concern that the stolen cars can also be used in the commission of other crimes, as well.

New York City mayor Eric Adams blamed social media for the spread of the criminal trend. Videos have been posted on TikTok, in particular, showing a technique in which a USB charging cable could be used to start a car through a partly disassembled ignition switch.

Grand larceny auto

“We see it as not only stealing a vehicle but it’s stealing the future of our young people,” Adams said. “When you are arrested for grand larceny auto it is a felony. It remains on your record. It impacts your life in a real way.”

The mayor reminded owners who have potentially vulnerable vehicles that Kia and Hyundai dealers can provide security upgrades to help protect their vehicles.

The two South Korean automakers have created a software patch to fix the problem, the automakers have said. Hyundai and Kia operate as separate companies in the United States, but Hyundai Motor Group owns a large stake in Kia, and various Hyundai and Kia models share much of their engineering.

The patch will be installed free of charge on models that need it, with software that requires an actual key in the ignition to turn the vehicle on. The software will also block the car from being started after the doors have been locked using the key fob remote control. The vehicle will need to be unlocked before it can be started.

The software also extends the length of the alarm sound from 30 seconds to a full minute. Hyundai dealers will also affix window stickers stating that the vehicle has anti-theft software installed.

Hyundai has begun providing the software immediately for the most popular — and most frequently stolen — vulnerable models. Kia said it has started to offer the update to some customers and expects to make it available to more affected vehicles. Hyundai also said it has initiated a program to reimburse owners for purchases of steering wheel locks.