Mobile SMS scams, also known as “smishing,” are snowballing at year-end in South Korea as cyber crooks scurry to devise more convincing tricks to steal valuable personal information such as users’ bank accounts, often putting together both online and offline tools.

According to the Korea Internet Security Agency, the number of new mobile scam apps stood at 2,278 as of Thursday, 150 times more than last year. The related financial damage soared tenfold to 54.5 billion won ($51.7 million) in a year, posing a real threat to unsuspecting Korean mobile users.

Korean users, many of whom quickly embraced smartphones, are now the easy target for such scammers. Cyber criminals increasingly upgrade their individually customized tactics, often proposing a phrase that calls for immediate action or to click on links in malicious mobile messages.

Experts warned that scam text messages often take the form of wedding invitations, package delivery status, discount coupons and links to eye-catching photos of celebrities and payment information.

Cyber security firms said that users should be extremely cautious about mobile phone messages such as “click here to collect your gift” accompanied by a link, as such links invariably lead to malicious sites that aim to steal confidential user data.

Similarly, many Korean smartphone users exchange messages about various social functions on SMS and mobile messengers such as Kakao Talk, and scammers are taking advantage of the widespread practice by producing similar messages that come with malicious codes or links.

Taking a step further, a new group of cyber criminals are piecing together online and offline clues to make their messages almost irresistible. They comb through major social media services to glean basic information about their targets such as email accounts, photos and their online friends.

As scam messages mutate at breakneck pace and include offline data, mobile carriers and government agencies are finding it difficult to keep those scammers at bay. In October, the Korean government set a new rule that defines Internet-based messages that are likely to come from spammers. Mobile carriers introduced more apps and solutions to filter out smishing attempts, only to see the volume of smartphone scam messages surge in recent weeks.

The country’s Cyber Terror Response Center said users should remain alert to any message with external links, install mobile security solutions and make sure the message in question is authentic, even if it comes with familiar names or information from social media services.

By Yoon Ha-youn and news reports
(yhayoun@heraldcorp.com)