It wouldn't proove that you committed the crime, since you could have gotten the currency through other means. It's also not certain proof that somebody committed a crime, since the currency could have been mined by someone for whoom this was legal.
On the other hand, if the DDoS target is located in a country where DDoS is illegal, then in that jurisdiction possession of the currency is certainly evidence that some unknown party participated in the DDoS. That might give police certain priviledges around confiscating any coins, depending on jurisdiction.
On the other hand, if the DDoS target is located in a country where DDoS is illegal, then in that jurisdiction possession of the currency is certainly evidence that some unknown party participated in the DDoS. That might give police certain priviledges around confiscating any coins, depending on jurisdiction.