The sinking Thursday of the flagship of Russia's Black Sea fleet has boosted Ukrainian morale - and sales of a postage stamp commemorating an earlier incident involving the cruiser - even as the Kremlin readies a fresh assault of the country's east and south.

And in another instance underscoring continued defiance as the war grinds into an eighth week, an art studio in Lviv in western Ukraine is auctioning a non-fungible token (NFT) based on a mug shot of oligarch Viktor Medvedchuk, a friend of Russian President Vladimir Putin who was recaptured by Ukrainian authorities this week.

The sinking of the Russian cruiser Moskva came shortly after Ukraine's national postal service released 1 million stamps depicting a Ukrainian fighter holding up a middle finger in front of the vessel. The "First Day" stamp was an interpretation of a Feb. 24 incident on Snake Island in which Ukrainian border guards reportedly told off the encroaching Moskva with colorful language as Russia launched its invasion.

As news emerged of the sinking of the Moskva - for which Ukrainian officials claimed responsibility - Ukrainians lined up outside a Kyiv post office in hope of snatching up the special stamp. Odessa's governor and the Ukrainian military said a Ukrainian missile attack sank the Russian warship - an assertion backed by Washington - while Moscow blamed a combination of a fire and bad weather.

Ukrainian President Volodymyr Zelensky took to social media to promote the commemorative stamp and an envelope that bore the same image. He mocked the damaged vessel, telling people using the stamps to remember that the Moskva "always travels only in one direction" - downward.

Images of the disheveled and handcuffed mogul Medvedchuk have also circulated widely since his recapture. Medvedchuk, who has been charged with treason, escaped house arrest shortly after the invasion, according to Kyiv.

Artists from the M81 Studio retooled a post-capture photo of Medvedchuk into what they termed "Warhol-style" pop art. Proceeds from the sale of the "Kremlin agent Medvedchuk for sale" NFT, which was trading at roughly $320, will be used to support Ukraine's defense efforts, the studio said.

"We are used to Medvedchuk being corrupt, but finally, he is being sold to benefit Ukraine, and not for his own enrichment," it added. An attorney for Medvedchuk did not immediately respond to a request for comment.

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The Washington Post's Peter Bejger contributed to this report.