SINGAPORE - Using the default personal identification number (PIN) 8888, Arivalagan Muthusamy gained access to multiple StarHub voicemail mailboxes that were used to take over WhatsApp accounts.
Some of these accounts were then used in cheating scams that saw three victims transfer $83,750 to a syndicate.
Arivalagan, 37, was sentenced to 10 months' jail on Monday (Aug 8) after he pleaded guilty to three charges under the Computer Misuse Act.
Arivalagan's alleged accomplice - Hoang Trung Khang - has been charged in court, and proceedings against the 28-year-old Vietnamese national is ongoing.
Deputy Public Prosecutor R. Arvindren said in court documents that Arivalagan and Hoang started working for a syndicate involved in cheating scams last year and targeted StarHub mobile users registered with a voicemail feature.
The voicemail mailbox could be accessed remotely by keying in the mobile number and PIN.
Arivalagan and Hoang called mobile numbers to test if the call gets diverted to voicemail when it goes unanswered.
Arivalagan then called StarHub's service hotline and keyed in the targeted victim's mobile number and the default PIN, which is available publicly.
After getting a message containing a one-time password, it was used to illegally take over WhatsApp accounts of the victim by registering a new account on another mobile device.
It was not clear in court documents how the one-time password messages were generated.
Said DPP Arvindren: "The accused knew that the purpose of taking over WhatsApp accounts of victims is to allow the syndicate to cheat individuals in the contact list of the victims' WhatsApp accounts by asking them to invest in gold or cryptocurrencies."
Between October and Nov 26 last year, Arivalagan accessed 40 WhatsApp accounts belonging to unknown owners in order to gain control of the accounts. He was paid $250 for each compromised account.
On Nov 27, Arivalagan accessed another 12 WhatsApp accounts following instructions from a syndicate member called Shawn. Arivalagan was provided a list of numbers to contact.
Three of the accounts were later logged out and could not be used by the syndicate, and Arivalagan was paid $2,250 for the nine other accounts.
The next day, he gained access to the StarHub voicemail mailbox belonging to Mr Amos Lye.
Mr Lye's WhatsApp account was then taken over by the syndicate, and his friends were then contacted by a member of the syndicate and were targeted as potential scam victims.
Multiple police reports were filed and Arivalagan was arrested on Nov 29 last year at a unit in Geylang, and Hoang was arrested in a hotel room in the same area the next day.
In his written sentencing submissions, DPP Arvindren asked for Arivalagan to be sentenced to 11 months' jail, saying the nature of his crimes is difficult to detect and the crime was fairly sophisticated.
For each charge, Arivalagan could have been fined $5,000 fine and jailed for up to two years.
