The issue focused on attempts by hackers to tamper with servers running websites hosted by IBM's ZeroAccess cybersecurity software and databases maintained by Level 3 Communications. In addition, computer programmers discovered flaws in systems built by Symantec Corp., providing hackers access to passwords for computers owned by corporations including JPMorgan Chase & Co., Barclays Plc and Deutsche Bank AG.

Security experts warned that hackers may soon exploit weaknesses in routers used by telecommunications carriers such as Verizon Wireless Inc., Sprint Corp., AT&T Inc., T