The report (in Chinese) says that the hacks are in the form of Trojan horse, aiming at info stealing but not destruction. The headquarter was not aware of it until a "falsified Chairperson's schedule" was circulated among the headquarter personnel. The person responsible for the circulation had no idea where it was from.
Tsai is both the president candidate and the chairperson of DPP's. Her office holds all the info regarding how the DPP had planned and is planning to campaign for the president and legislator elections early next year, including how to deploy the resources, who is gonna take charge of what, etc.
All these info were stolen, alone with critical private info like user names, passwords, etc, of the headquarter personnel's.
The report didn't mention how long the stealing had been going on. A Trojan horse type of hack usually stays in the victim computer for a long time while gathering info. It's likely that the DPP has been operating like an open book for a long time in the eyes of her opponents.
The DPP had the ip's traced, and found that the hacks came from 3 sources:
1. China's national Xinhua News Agency (XNA);
2. Individual hackers;
3. Some "special group" inside Taiwan;
The XNA denied any involvement. But the investigation reveals attacks came from the XNA in Beijing and going through the XNA branch in Malaysia.
The 3rd group is revealed to be from the Research, Development and Evaluation Commission, an office in Executive Yuan (RDEC, 行政院研考會) of the Ma Ying-jeou government.
There's no comment from Ma government so far. The DPP said they don't want to speculate anything now.
They do complain about the reluctance of the police in pursuing this case. A police office was quoted as saying, "don't pull the trigger only because you see a shadow," when he/she was asked to investigate.
This is not the first time the police plays dormant to threats against the DPP.
There were several online assassinating calls against Ma Ying-jeou in the past. Each of them was dealt with in a lightning pace --- whoever made that claim was caught by the police the same or the next day.
But when the target was Tsai, it's a different story.