Microsoft says it has found destructive malware in Ukraine government agency systems. 

A recent cyber attack left official websites defaced with a warning to “be afraid and expect the worst”, coming as Russia posts increasing troop numbers near Ukraine's borders.

Ukraine and US officials have warned that Russia is planning a new military assault on Ukraine.

Microsoft says it has observed destructive malware in systems belonging to several Ukrainian government agencies and organisations linked to the Ukrainian government.

Malware is reportedly affecting key Ukrainian government agencies that provide critical executive branch or emergency response functions. 

An IT firm that manages websites for public and private sector clients, including government agencies, has been impacted too. 

The malware is disguised as ransomware and can render infected computer systems inoperable if activated by the attacker.

The malware is similar to the type used by Russian intelligence, but in the case is coming from Belarus, according to a senior Ukrainian security official.