Wassana Nanuam reports that a self-described “hacktivist” who calls himself “9Near” has been identified:
A hacker who claimed to have obtained the personal data of 55 million Thais is an army officer who appears to have acted alone, authorities said yesterday.
[…]
Mr Chaiwut said investigators had identified the hacker and are working with his supervisors to bring the suspect in for questioning. The minister did not disclose the suspect’s name, but said he is an army sergeant major second class.
Read more at Bangkok Post. The 9Near.org site, where the hacktivist had posted messages, does not appear to be reachable today. The Bangkok Post reports that the site was blocked.
And while the Bangkok Post did not name the suspect, Khaosod English did name him as Sgt. Maj. Khemarat. That site also reports:
However, national police commissioner Damrongsak Kittiprapas said Friday the data was leaked from the government’s Mor Prom application, which was used by citizens for vaccination services during the coronavirus pandemic.