SecuLetter

SecuLetter is a South Korean cybersecurity company that has focused exclusively on Content Disarm and Reconstruction (CDR) technology since its founding in 2015. Rather than trying to detect malware in email attachments and files, CDR strips a file down to its known-safe elements and rebuilds a clean version — removing the need to make a detect/allow decision on unknown or novel threats, a meaningful alternative to signature- and behavior-based scanning.

Headquartered in Seongnam, South Korea, in the Seoul metropolitan area, the company raised an $8M Series B in 2020 and completed an IPO on the KOSDAQ exchange in August 2023 (ticker 418250), raising roughly KRW 13.9 billion — a notable milestone, since most CDR vendors globally remain privately held.

SecuLetter’s named customers include BNK Busan Bank, and it reports deployments at South Korea’s Ministry of Science and ICT, National Health Insurance Service, and National Pension Service — a customer base concentrated in Korean government and financial-sector accounts rather than broad international enterprise adoption, though the company states it is expanding into Japan, Southeast Asia, and the Middle East.

Gartner has named SecuLetter a Representative Vendor in its CDR Market Guide, the only Korea-headquartered company on that list by the company’s own account — a meaningful, if not head-to-head competitive, piece of independent recognition. SecuLetter also states it holds the largest CDR patent portfolio in Korea, a claim tied to actual patent filings rather than pure marketing language, though this review did not independently verify the patent count.