Ukraine claims to have successfully hacked Russian military servers and gained access to highly sensitive information.

According to an official statement from the Defence Intelligence of Ukraine, the hack has allowed Ukraine to gain possession of "the information security and encryption software" used by Russia's Ministry of Defence (Minoborony), as well as secret documents, reports, and instructions exchanged between over 2,000 units of Russia's security services.

Posting images of some of the breached Russian data on Telegram, Ukraine said that an analysis had helped its forces to identify the generals and other senior officers that make up the various Russian defence units, as well as deputies, assistants and specialists.

"The information obtained allows us to establish the complete structure of the system of the Russian Ministry of Defense and its units," claimed the Defence Intelligence of Ukraine (known as the GUR).

The hack by Ukraine has not been independently verified, but if true it would clearly be extremely embarrassing as well as potentially damaging for Minoborony.

To compound the stress that Russian ministry officials must be feeling, Ukraine claimed that stolen documents included official files belonging to Russia's deputy defense minister, Timur Vadimovich Ivanov.

Ukraine claims that Ivanov, who works as a deputy to Russian defence minister Sergei Shoigu, "played an important role in the success of the cyber-attack."

What that might mean remains anybody's guess.

Was Ivanov phished?  Did he reuse a password?  Was his computer compromised in a targeted attack that helped Ukrainian hackers establish a foothold for remote access, allowing them to gain access to Russian systems?

Or, are we seeing Ukraine engaging in some crafty psy-ops, deliberately trying to undermine trust within the Russian Ministry of Defence's leadership to make them a less effective rival?

We may never know for certain.

What is clear is that both Russia and Ukraine are very actively engaged in conflict in cyberspace, just as they are on the physical battlefield. In recent months, we have heard that Russian hackers were inside Ukraine's telecoms for many months and that critical infrastructure such as power grids have been targeted. Meanwhile, Ukrainian-backed hackers have reportedly crippled Russian water utility plants and disrupted Russia's tax service.