WARSAW—The email accounts of about a dozen members of Parliament were hacked recently, Polish counter-intelligence said on Friday, disclosing further details of one of the biggest cyberattacks on the country in recent years. The revelations come two weeks after the authorities said top Polish government officials had been hit by a far-reaching cyberattack conducted in June that affected over 100 email accounts of current and former government officials. Among the accounts reportedly breached was the personal account of the prime minister’s top aide Michal Dworczyk, an intrusion that spurred a series of leaks that have led to opposition criticism of officials for using private accounts to exchange confidential documents. In a statement on Friday, counter-intelligence authorities said members of parliament hit in the hacking come from almost every parliamentary opposition grouping, and those affected had been notified and had received cybersecurity training. The statement did not identify the lawmakers hacked. …