The company revealed the breach via its website, but did not disclose the precise nature of attack. Soon after, it issued another statement explaining the root cause of the problem had been identified and that the company was working on a fix.
At the time of writing, the company’s internal network still appears to be affected, with a post of the company website explaining the firm is still unable to read emails.
According to a ZDNet report, although the attack has not officially been classified, experts believe ransomware was likely responsible.
Cybersecurity firm Bad Packets believes Elexon made the mistake of not updating Pulse Secure, an enterprise-level SSL VPN that its employees use to access internal networks.
Allegedly, this version of Pulse Secure was found to be vulnerable last summer, when both US and UK cybersecurity agencies issued patch warnings.