A White House official who asked The Washington Post not to disclose his identity said that the intruders did not damage any of the systems and that, to date, there is no evidence the classified network was hacked. All of the US intelligence, namely FBI,  Secret Services and National Security Agency are working together to investigate the intrusion however no one is commenting on when and how the breach happened. White House computers networks are regularly being targeted by cyber attacks, anti American interests and counter revolutionaries,  however up to this day, all resulted in failed attempts. The breach which was discovered 2-3 weeks back caused temporary disruptions in some of the computer network services. Some White House staff were asked to change their passwords and email systems were restarted after a minor delay however the White House Intranet and VPN access were shut down for some time. The news of White Houses computer network intrusion came appeared just after a another report from the FireEye security research firm, which said that Russian hackers were involved in a sophisticated cyber espionage program were malicious codes were inserted into the computer networks  of a firm harboring U.S. military secrets. Earlier this month another security research firm  had reported that Russia backed cyber criminals were involved in exploiting a unknown flaw in Microsoft’s Windows operating system called ‘Sandworm’ to spy on NATO and Governments across the Europe. The Sandworm 2 flaw is yet to be patched by Microsoft and all systems excluding Windows Server 2003 are vulnerable to this zero-day exploit.