WASHINGTON: US Homeland Security Secretary Jeh Johnson said technical problems reported on Wednesday by United Airlines and the New York Stock Exchange were apparently not related to 'nefarious' activity. 'I have spoken to the CEO of United, Jeff Smisek, myself. It appears from what we know at this stage that the malfunctions at United and the stock exchange were not the result of any nefarious actor,' Johnson said during a speech at the Center for Strategic and International Studies, a Washington think tank. 'We know less about the Wall Street Journal at this point, except that their system is in fact up again,' he added. Early on Wednesday morning, United flights were grounded after a router issue degraded connectivity in the airline's networks. Just as United was bringing its systems back on-line, trading on the New York Stock Exchange came to a halt due to a technical problem and the Wall Street Journal's website experienced errors. Meanwhile, Secretary Johnson has called for National Data Breach Reporting System to replace 'patchwork' of state laws, enhanced criminal penalties for hacking. The White House and the US Treasury Department are monitoring the 'ongoing issue' at the New York Stock Exchange and President Barack Obama has been briefed on the matter, a White House official said on Wednesday. The NYSE Group, which includes the New York Stock Exchange, has suspended trading in all securities because of technical difficulties.   READ ALSO:  Wall Street lower as NYSE trading stays suspended