I found this in my recent history. The word "regietry" is not a typo on my part, this is actually what it says in the log.
Actor: windows\system32\svchost.exe
Actor PID: 708
target: hkey_local_machine\system\currentcontrolset\enum\root\legacy_bhdrvx64\0000\control\
target PID: 0
Action: Set regietry security key.
Reaction: Unauthorized access blocked.
Current OS is Windows 7 SP1 along with NIS 2011.
Any insight regarding this event will be gladly appreciated.
xNJLM
2
ACTOR: C:\WINDOWS\SYSTEM32\SVCHOST.EXE
ACTOR PID: 932
Target: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_EECTRL\0000\CONTROL
TARGET PID: 0
Action: Set Regietry Security Key
Reaction: Unauthorized Access Blocked
Whats all this happening in my Norton logs?
yank
3
Hi rao,
Please see Son of Jive's responses in the following thread - he explains it much better than I could. 
http://community.norton.com/t5/Norton-360/Unauthorized-Access-Blocked-LEGACY-BHDRVX64/td-p/669007