Antrim and Newtownabbey Borough Council has revealed criminals locked its computers in 2015/16 and demanded a ransom.
The findings, which were obtained after Johnston Press submitted a Freedom Of Information (FOI) request, detail how the ransom was demanded before the criminals would release the computers back into the council’s usage.
The local authority said it suffered one successful attack in the past three years. In 2015/16 it suffered a ransomware attack - where a virus designed by criminals locked computers until an online ransom is paid.
On that occasion, the criminals demanded payment in the internet currency ‘bitcoin’, however none was paid.
The problem was overcome by restoring information on the computers affected using back-up information, the council said.
The attack was not reported to police or any other authorities and no attacker was ever traced or convicted.
Commenting on the issue, a council spokesperson said: “Council recognises that the number of cyber threats is on the increase and as such utilises many industry leading products to protect its network and endpoints.
“Council has a managed firewall solution with regular penetration testing and this provides a fully monitored network security perimeter to ensure its network is as secure as possible.”
The spokesperson added: “A next generation endpoint security solution is used which provides protection from various threats, including system- and memory-based attacks, malicious documents, zero-day malware, privilege escalations, scripts and potentially unwanted programs. It also detects and prevents unusual activity across the network.
“Additionally, other software solutions continually monitor server and network performance, reporting any high or unusual activity levels and allowing any appropriate remedial action to be taken.”