UK organisations are being urged to bolster their defences amid fears cyber attacks linked to the conflict in Ukraine could move beyond its borders.
The National Cyber Security Centre (NCSC) has issued new guidance, saying it is vital companies stay ahead of a potential threat.
The centre said it was unaware of any specific threats to UK organisations.
It follows a series of cyber attacks in Ukraine which are suspected to have involved Russia, which Moscow denies.In December 2015, engineers in Ukrainian power stations saw cursors on their computer screens moving by themselves. They had been hacked. Hundreds of thousands of people lost power for hours.
It was the first time a power station had been taken offline, a sign that cyber intrusions were moving beyond stealing information into disrupting the infrastructure on which everyday life depends. Russia was blamed