MOSCOW — Shifting from his previous blanket denials, President Vladimir V. Putin of Russia said on Thursday that “patriotically minded” private Russian hackers could have been involved in cyberattacks last year to help the presidential campaign of Donald J. Trump.

While Mr. Putin continued to deny any state role, his comments to reporters in St. Petersburg were a departure from the Kremlin’s previous position: that Russia had played no role whatsoever in the hacking of the Democratic National Committee and that, after Mr. Trump’s victory, the country had become the victim of anti-Russia hysteria among crestfallen Democrats.