As far as I can tell, this story is false. This is linked through MSN but not published by them. The direct link is here and it’s published by essanews.com. I can’t find any fact check info on them but they’re owned by a giant Polish media company (Wirtualna Polska). A few years ago, Wirtualna Polska were caught publishing pro-government stories under fake names. This is also reported by Knewz.com, citing this story as a source and framing the Alaska claim as speculation. No one else seems to be reporting this, though it would be big, ridiculous news.

I think the timeline is that Putin ordered a hunt for Russian/Soviet property. Then Igor Sushko (Winds of Change guy) speculated that it had implications for the sale of Alaska. Reading the translation, it appears to be pretty wild speculation. Anyway, then this story is published saying that Putin signed a specific decree declaring the Alaska sale illegal. I can’t find any reference to a specific decree about Alaska.