"Your mail has arrived" scam leaves victims facing losses of tens of millions of won as letter phishing makes a comeback

[Financial News] Letter phishing, a voice-phishing scam involving stickers that resemble post office notices and prompt victims to call a number themselves, is spreading again. Victims may mistake the stickers for simple mail-delivery notices and suffer losses of tens of millions of won, prompting calls for caution.
According to the Korean National Police Agency on the 26th, letter phishing is a voice-phishing technique in which criminals attach forged notices of mail arrival to doors or mailboxes and induce victims to call the number listed on the notice. The Korean National Police Agency issued a related alert in April 2025 and publicized the scam's methods and prevention tips.
The scam unfolds in several stages. Fraudsters attach a notice modeled on a post office form outside a victim's home. When the victim calls the listed number, the fraudster poses as a postal worker and directs the victim to another contact. The victim is then threatened by someone impersonating a prosecutor from the Seoul Central District Prosecutors' Office or another investigative agency, who says, "Your account has been involved in a crime." The fraudster then induces the victim to install a malicious app and steals cash, gift certificates, virtual assets or other valuables.
The methods used to defraud victims also vary. In one case in Seoul, a woman in her 20s was made to install Telegram, forced to engage in video calls for 24 hours and even asked to film herself nude under the pretext of undergoing a physical examination. Authorities also confirmed a case in which a victim was made to purchase a standalone mobile phone without a malicious-app blocking function, after which the victim's phone information was stolen.
Similar crimes have been reported before. In December 2024, someone impersonating a postal worker from Mansu Danji Post Office in Incheon attempted to obtain a victim's address and personal information. Gyeongju Police Station also arrested and detained members of a voice-phishing organization that used forged notices of mail arrival. According to Korean National Police Agency statistics, voice-phishing losses in Seoul increased from 160.4 billion won in 2023 to 402.8 billion won in 2025, a 2.5-fold increase over two years.
There are also signs to look for when distinguishing a fake notice. Under Article 31 of the Postal Service Act, postal workers deliver mail only to the address written on the item and therefore do not separately ask the recipient where it should be delivered. People should also avoid immediately calling the number listed on the notice.
If you find a suspicious notice, it is safest to contact the post office directly through its official representative number rather than calling the number printed on the notice. Investigative agencies do not ask people over the phone to install apps or enter personal information. If a loss has occurred or a situation seems suspicious, report it to the Korean National Police Agency's Cybercrime Reporting System or the Financial Supervisory Service call center at 1332.
[email protected] Han Seung-gon Reporter