Before leaving his employment with IT vendor NCS in August 2012, Abdul Gafoor Jahangeer Basha harvested user credentials from a source file, for a computer system under his care.
Finding vulnerabilities in the software coding for the online appointment system of the Manpower Ministry's employment pass services centre, which he had saved onto his personal laptop, he later logged in and amended or deleted a total of 972 records by executing rogue commands.
His actions forced the ministry to deploy a team to verify records and help pass applicants unable to log in.
A team of IT staff was also deployed to conduct investigations and undo the changes.
The total manpower cost incurred by MOM in the process was $19,800, with an additional $616.80 paid to the vendor for the ministry's call centre, which received 257 inquiries from affected applicants.
Yesterday, Abdul Gafoor, now 34, was fined $86,000 by a district court for numerous offences under the Computer Misuse Act.
These were committed between October and December 2012, following the early termination of his contract due to unrelated performance issues. However, these included accessing text files, logging in to the system using other users' credentials and modifying records.
He pleaded guilty to 34 charges, with another 79 taken into consideration.