Letter phishing, a voice phishing scheme using forged mail delivery notices, is resurging ahead of the Chuseok holiday, the Korean National Police Agency said on the 25th. Scammers attach fake notices to doors or mailboxes and persuade recipients to call a number printed on the document. The caller poses as a mail carrier, then transfers the victim to another scammer impersonating a prosecutor at the Seoul Central District Prosecutors' Office or another investigative body. Victims are told their accounts are connected to crimes and pressured to install malicious apps, surrender personal information or hand over cash, gift certificates and cryptocurrency. Police first issued a formal warning about the method and prevention measures in April 2025. Seoul voice phishing losses rose 2.5-fold from 160.4 billion won in 2023 to 402.8 billion won in 2025. Authorities advise residents not to call numbers on suspicious notices, to verify deliveries through a post office's main number and to report suspected fraud immediately.