Ukraine's SBU Security Service has thwarted an attempt by Russian special services to conduct a cyber attack on network equipment belonging to LLC Aulska chlorine station (the village of Auly, Dnipropetrovsk region), which provides chlorine to water treatment and sewage plants for chlorination throughout Ukraine and is regarded as critical infrastructure.

"Specialists of the cyber security service established minutes after [the incident] that the enterprise's process control system and system for detecting signs of emergencies had deliberately been infected by the VPNFilter computer virus originating from Russia. The continuation of the cyber attack could have led to a breakdown in technological processes and a possible accident," the SBU said on its Facebook page on Wednesday.

The SBU said the aim of the attack was to block stable operation of the station, which provides liquid chlorine for water treatment.

The SBU said its agents together with a telecoms provider and workers of the station managed to prevent a potential man-made disaster, adding Russia special forces were behind cyber attacks with the same virus on the public and private sectors in May 2018.

VPNFilter is multi-level, modular, malicious software with versatile capabilities used in both cyber intelligence and destructive cyber attacks.