Ukraine has suffered a string of cyberattacks in recent
weeks which Kyiv has blamed on Russia. Moscow, which is caught up in a mounting
confrontation with the West over Ukraine, has denied any involvement.
Ukraine's government-run cybersecurity agency CERT-UA said
on Monday it had found warnings on a hacking forum.
One message had "referred to the lease of servers to
prepare new attacks on the websites of the public sector, the banking sector
and the defence sector," it said.
Ukraine said last week Russia was likely behind an attack
which downed the web portal of the defence ministry and disrupted banking and
terminal services at large state-owned lenders.
The online attacks and warnings of more come as Western
countries accuse Russia of planning an invasion of neighbouring Ukraine. Moscow
denies planning any attack but has demanded security guarantees including a
promise that Ukraine would never join Nato.
Ukraine has previously accused Russia of launching
cyberattacks to sow panic and crash its financial system.