Companies need to know when they are hacked

Recently several large U.S. companies were hacked online and like other victims of similar attacks, they were not aware until well after the attack happened. In some cases it was months. Online security firm Mandiant says, often attacks are blamed on malware, but they say 46% of compromised machines have no malware on them. Mandiant says hackers can navigate through conventional safeguards easily leaving little or no trace.