"I'll keep your Bitcoin safe"... Gang swindles billions from acquaintance

Four individuals who stole 45 Bitcoins by obtaining the password to an acquaintance's cryptocurrency wallet under the pretense of safe storage have been caught. The value of the stolen Bitcoins was approximately 2.4 billion KRW at the time, and approximately 6 billion KRW at the current rate.

The Seoul Metropolitan Police Agency's Cyber Investigation Unit announced on the 25th that they arrested four individuals, including Mr. A, on charges of violating the Information and Communications Network Act and fraud using computers under the Act on the Aggravated Punishment of Specific Economic Crimes, and have sent two of them to the prosecution under detention.

Mr. A (34) and Mr. B (31) are accused of deceiving a long-time acquaintance to obtain the 'mnemonic code' of their electronic wallet and then siphoning off 45 Bitcoins (worth approximately 6.07 billion KRW at the current rate) to their wallets in January last year. A mnemonic code is a combination of 12 to 24 English words used to recover an electronic wallet. With just these words, all virtual assets in the wallet can be restored on another device.

The victim accepted the advice of Mr. A and Mr. B in January 2023 to move the Bitcoins to a 'cold wallet' (offline wallet) for safer storage. They persuaded the victim by saying, "Writing the mnemonic code on paper is vulnerable to fire, so it's safer to record it on a metal plate." Trusting their words, the victim entrusted all related tasks to them and even recited the mnemonic code.

However, they secretly recorded their conversation with the victim on a mobile phone and used it to transfer 45 Bitcoins from the victim's wallet to their own about a year later. They involved a Thai national in the crime and used a 'mixing' method, transferring the Bitcoins multiple times to make it difficult to trace the source. They also 'laundered' 20 Bitcoins by exchanging them for Thai Baht in the local Thai black market.

The police identified the suspects after tracking the Bitcoins for about 10 months. In February this year, they arrested the Thai accomplice at Incheon International Airport and sent him to the prosecution under detention. Mr. A, who led the crime, was also handed over to the prosecution in custody on the 17th. The police have recovered 25 of the stolen Bitcoins and plan to confiscate and collect all remaining criminal proceeds.

Reporter Lee Song-ryeol, Hankyung.com yisr0203@hankyung.com