Update

Harlan proposed to search for ‘system\’. I did and added stats below.

Old post

Corey asked on Twitter about stats for registry keys so I grepped the strings extracted from samples for traces of related artifacts. Since it’s a non-trivial task (at least dynamic analysis are needed to confirm which reg keys are really used during run-time and even more work is needed to confirm which keys are actually malware-related) I only searched for the ‘Software\’  string assuming that is is a decent keyword to start with. If you have better ideas, please let me know.

These are above 1000 occurrences for ‘SOFTWARE\’:

 112294 SOFTWARE\Borland\Delphi\RTL
  89263 Software\Microsoft\Windows\CurrentVersion\Run
  81916 Software\Borland\Delphi\Locales
  80672 Software\Borland\Locales
  53495 Software\Microsoft\Windows\CurrentVersion
  48312 SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  45933 Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
  31554 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
  21968 Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
  21788 Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
  21420 Software\Microsoft\Internet Explorer\Main
  20350 SOFTWARE\
  18188 Software\Microsoft\Windows\CurrentVersion\Policies\System
  17461 Software\
  16913 SOFTWARE\Microsoft\Windows\CurrentVersion
  16271 SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
  11711 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
  10785 SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
  10471 SOFTWARE\Microsoft\Windows\CurrentVersion\Setup
  10305 Software\Microsoft\Windows\CurrentVersion\Internet Settings
   9981 Software\Microsoft\Windows\CurrentVersion\Internet Settings\User Agent\Post Platform
   9894 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\SuperHidden
   9443 SOFTWARE\Microsoft\Windows NT\CurrentVersion
   9285 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\HideFileExt
   8805 Software\%s
   8371 Software\Microsoft\Windows\CurrentVersion\RunServices
   8215 SOFTWARE\Microsoft\Internet Explorer\Main
   8206 Software\Microsoft\Windows\CurrentVersion\Policies\Network
   7826 Software\Microsoft\Windows\CurrentVersion\RunOnce
   7614 Software\Microsoft\Windows\CurrentVersion\Policies\Comdlg32
   7465 Software\Microsoft\Internet Explorer
   7252 SoftWare\Microsoft\Windows\CurrentVersion\Run
   7183 SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes
   6988 SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
   6918 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\NOHIDDEN
   6187 Software\WinLicense
   5573 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellExecuteHooks
   5510 Software\Microsoft\Active Setup\Installed Components\
   5209 HKLM\Software\Microsoft\Windows\CurrentVersion
   5184 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
   4925 Software\Microsoft\Internet Explorer\PageSetup
   4886 Software\Microsoft\Windows NT\CurrentVersion\Winlogon
   4739 Software\Microsoft\Windows\CurrentVersion\Policies\WinOldApp
   4625 Software\Microsoft\OLE
   4568 SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\
   4396 SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
   4348 Software\Microsoft\Windows\CurrentVersion\explorer\Browser Helper Objects\
   4182 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\explorer\run
   3994 Software\Classes\
   3933 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
   3739 Software\Microsoft\Windows\CurrentVersion\run
   3704 Software\Fenomen Games\Game Downloader\1.1\List
   3533 SOFTWARE\Microsoft\Windows NT\CurrentVersion\Svchost
   3532 SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
   3506 Software\WinRAR SFX
   3498 SOFTWARE\SweetIM\Messenger
   3492 SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322
   3420 Software\MediaGet
   3420 SOFTWARE\MediaGet
   3408 Software\Mediaget
   3408 SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{70B96CD0-FDF2-489E-8FA0-0F92ED599368}
   3407 Software\Microsoft\Windows\CurrentVersion\Uninstall\MediaGet
   3316 SOFTWARE\BabylonToolbar\BabylonToolbar\Instl
   3302 Software\BioWare\NWN\Neverwinter
   3291 SOFTWARE\Microsoft\Security Center
   3281 SOFTWARE\Microsoft\NET Framework Setup\NDP
   3268 Software\Policies\Microsoft\Internet Explorer\Control Panel
   3238 Software\Microsoft\Windows\CurrentVersion\explorer\ShellExecuteHooks
   3207 Software\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad
   3149 Software\Microsoft\Windows NT\CurrentVersion\Windows
   2978 Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\run
   2899 SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
   2764 Software\Microsoft\Windows NT\CurrentVersion
   2763 Software\Microsoft\Internet Account Manager\Accounts
   2749 Software\Microsoft\Internet Explorer\TypedURLs
   2746 SOFTWARE\Microsoft\Internet Explorer
   2686 Software\Microsoft\Windows\CurrentVersion\Uninstall
   2643 Software\Microsoft\Windows\CurrentVersion\policies\explorer\run
   2619 Software\Microsoft\Windows\CurrentVersion\App Paths
   2527 Software\Microsoft\Windows\CurrentVersion\WinTrust\Trust Providers\Software Publishing\Trust Database\0
   2513 Software\Microsoft\Windows\ShellNoRoam\MUICache
   2478 Software\Wine
   2402 Software\Microsoft\Windows\CurrentVersion\Internet Settings\User Agent
   2400 Software\Microsoft\Windows\CurrentVersion\Uninstall\
   2339 Software\Valve\Half-Life\Settings
   2308 SOFTWARE\Microsoft\Windows NT\CurrentVersion\Hotfix\Q246009
   2299 Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
   2249 SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
   2244 SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
   2234 Software\Ask.com.tmp
   2133 Software\Valve\CounterStrike\Settings
   2107 SOFTWARE\Microsoft\Shared Tools\MSConfig\startupreg
   2099 SOFTWARE\Microsoft\Shared Tools\MSConfig\startupfolder
   2098 Software\Activision\Soldier of Fortune II - Double Helix
   2033 SOFTWARE\Microsoft\Windows\CurrentVersion\
   1941 Software\Eugen Systems\The Gladiators
   1931 Software\AppDataLow
   1866 SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop
   1851 SOFTWARE\WinRAR
   1842 Software\Microsoft\Windows\CurrentVersion\Explorer
   1841 Software\ASProtect\Key
   1833 Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\%s
   1829 Software\Unreal Technology\Installed Apps\UT2003
   1822 SOFTWARE\Microsoft\Windows\CurrentVersion\Run\
   1813 Software\Valve\Gunman\Settings
   1811 Software\JoWooD\InstalledGames\IG2
   1807 Software\Electronic Arts\EA GAMES\Generals\ergc
   1802 Software\Microsoft\Protected Storage System Provider
   1798 Software\Silver Style Entertainment\Soldiers Of Anarchy\Settings
   1791 Software\Electronic Arts\EA Sports\FIFA 2003\ergc
   1761 Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\NewStartPanel
   1687 Software\Microsoft\Internet Explorer\New Windows\Allow
   1686 SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\
   1665 Software\Microsoft\Internet Explorer\SearchScopes
   1646 SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
   1617 Software\Westwood\Tiberian Sun
   1606 Software\Westwood\Red Alert 2
   1576 Software\3d0\Status
   1571 Software\Electronic Arts\EA Sports\NHL 2003\ergc
   1571 Software\Electronic Arts\EA Sports\NHL 2002\ergc
   1570 Software\Techland\Chrome
   1570 Software\Microsoft\Windows\CurrentVersion\Uninstall\Google Chrome
   1570 Software\Microsoft\Windows
   1565 Software\Electronic Arts\EA Sports\FIFA 2002\ergc
   1563 Software\Electronic Arts\EA GAMES\Battlefield 1942\ergc
   1560 Software\Microsoft\Internet Explorer\IntelliForms\Storage2
   1560 Software\Microsoft\%s %s Manager\%ss
   1560 Software\Electronic Arts\EA GAMES\Battlefield 1942 Secret Weapons of WWII\ergc
   1559 Software\Electronic Arts\EA GAMES\Battlefield 1942 The Road to Rome\ergc
   1555 Software\Electronic Arts\EA Sports\Nascar Racing 2002\ergc
   1553 Software\Electronic Arts\EA Sports\Nascar Racing 2003\ergc
   1545 Software\Westwood\Red Alert
   1541 Software\Fenomen Games\Game Downloader\1.1\Completed
   1534 Software\Illusion Softworks\Hidden & Dangerous 2
   1528 Software\Microsoft\Windows\CurrentVersion\Explorer\SharedTaskScheduler
   1515 Software\Unreal Technology\Installed Apps\UT2004
   1502 Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\
   1490 Software\Electronic Arts\EA GAMES\Battlefield Vietnam\ergc
   1483 SOFTWARE\Mozilla\Mozilla Firefox
   1481 Software\Red Storm Entertainment\RAVENSHIELD
   1478 Software\Westwood\NOX
   1478 Software\Electronic Arts\EA GAMES\Command and Conquer Generals Zero Hour\ergc
   1475 Software\IGI 2 Retail
   1474 Software\Electronic Arts\EA GAMES\Need For Speed Hot Pursuit 2
   1472 Software\Electronic Arts\EA GAMES\Need For Speed Underground\ergc
   1461 Software\Electronic Arts\EA GAMES\Medal of Honor Allied Assault Spearhead\ergc
   1461 Software\Electronic Arts\EA GAMES\Medal of Honor Allied Assault Breakthrough\ergc
   1460 Software\Electronic Arts\EA GAMES\Shogun Total War - Warlord Edition\ergc
   1460 Software\Electronic Arts\EA GAMES\Medal of Honor Allied Assault\ergc
   1459 Software\Electronic Arts\EA GAMES\Black and White\ergc
   1458 Software\Policies\Microsoft\Internet Explorer\Restrictions
   1458 Software\Electronic Arts\EA GAMES\Global Operations\ergc
   1458 Software\Electronic Arts\EA Distribution\Freedom Force\ergc
   1457 Software\Electronic Arts\EA GAMES\James Bond 007 Nightfire\ergc
   1456 Software\Yahoo\Pager\View\YMSGR_Launchcast
   1433 SOFTWARE\Classes\http\shell\open\commandV
   1405 Software\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop
   1373 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
   1373 SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\
   1351 SOFTWARE\Microsoft\Windows NT Script Host\Microsoft DxDiag\WinSettings
   1342 SOFTWARE\Vitalwerks\DUC
   1337 SOFTWARE\Policies\Microsoft\Windows\Installer
   1300 Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\EscDomains\
   1296 SOFTWARE\CnNuo20\socket
   1287 Software\Microsoft\Windows\Shell\Associations\UrlAssociations\http\UserChoice
   1246 SOFTWARE\Microsoft\Windows\CurrentVersion\netcache
   1246 SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
   1224 SOFTWARE\Microsoft\Active Setup\Installed Components
   1214 Software\Yahoo\Pager\View\YMSGR_buzz
   1195 Software\Microsoft\Internet Explorer\TypedAddress
   1190 SOFTWARE\Microsoft\IDSCNP
   1177 Software\Microsoft\Windows\CurrentVersion\Run\
   1170 SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\
   1165 SOFTWARE\Microsoft\Active Setup\Installed Components\
   1165 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows]
   1150 Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
   1136 Software\Microsoft\Internet Explorer\Desktop\General
   1129 Software\EGDHTML
   1125 Software\Microsoft
   1121 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run\
   1111 Software\Microsoft\Internet Explorer\Toolbar
   1102 Software\Microsoft\Windows\CurrentVersion\Network\LanMan
   1075 Software\Microsoft\Internet Explorer\Toolbar\WebBrowser
   1059 Software\Zylom\MyZylom\Credentials
   1058 Software\Microsoft\Windows\CurrentVersion\
   1054 SOFTWARE\Microsoft\Shared Tools\MSConfig\startupreg\
   1049 SOFTWARE\Microsoft\Shared Tools\MSConfig\startupfolder\
   1040 Software\microsoft\windows\currentversion\Explorer\shellexecutehooks
   1039 Software\Borland\Database Engine
   1034 Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
   1034 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run
   1023 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Ratings\PICSRules\.Default\0\PRPolicy\
   1023 SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Ratings\PICSRules\.Default\0\PRPolicy
   1016 Software\Yahoo\Pager\View\YMSGR_Calendar
   1016 Software\Microsoft\Windows\CurrentVersion\App Paths\IEXPLORE.EXE
   1013 Software\AppDataLow\RivalGamingData
   1009 Software\Classes\CLSID\%s\InprocServer32
   1002 Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\ClassicStartMenu

'SYSTEM\'
  52751 System\CurrentControlSet\Control\Keyboard Layouts\%.8x
  14516 SYSTEM\CurrentControlSet\Services\
   6913 SYSTEM\CurrentControlSet\Control\Keyboard Layouts\
   5894 SYSTEM\CurrentControlSet\Services\%s
   4994 SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
   4170 SYSTEM\CurrentControlSet\Control\Lsa
   3361 SYSTEM\CurrentControlSet\services\SharedAccess\Parameters\FirewallPolicy\FirewallRules
   3081 SYSTEM\CurrentControlSet\Control\ProductOptions
   3022 System\CurrentControlSet\Control\Session Manager
   2722 SYSTEM\CurrentControlSet\Control\Terminal Server
   2575 SYSTEM\CurrentControlSet\Services
   2547 SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
   2486 System\CurrentControlSet\Services\
   2388 System\CurrentControlSet\Control\Session Manager\FileRenameOperations
   1468 SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
   1416 SYSTEM\
   1397 system\sservice.exe
   1341 SYSTEM\CurrentControlSet\Services\TermService
   1316 SYSTEM\CurrentControlSet\Services\TermDD
   1303 SYSTEM\CurrentControlSet\Control\Session Manager
   1215 SYSTEM\CurrentControlSet\Services\lanmanserver\parameters
   1213 SYSTEM\CurrentControlSet\Control\Terminal Server\Wds\rdpwd\Tds\tcp
   1203 SYSTEM\ControlSet001\Services\
   1171 SYSTEM\CurrentControlSet\Services\SharedAccess
   1135 system\
   1086 SYSTEM\CurrentControlSet\Control\Terminal Server\RDPTcp
    964 SYSTEM\ControlSet001\Services\%s
    929 SYSTEM\CurrentControlSet\Services\lanmanworkstation\parameters
    928 SYSTEM\CurrentControlSet\Services\%s\Performance
    920 SYSTEM\CurrentControlSet\Services\wscsvc
    914 SYSTEM\ControlSet001\Control\SafeBoot
    882 System\CurrentControlSet\Control\Windows
    828 SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\{4D36E967-E325-11CE-BFC1-08002BE10318}
    822 SYSTEM\CurrentControlSet\Control\SafeBoot\Network\{4D36E967-E325-11CE-BFC1-08002BE10318}
    757 SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
    702 SYSTEM\CurrentControlSet\Services\EventLog\Application\
    695 SYSTEM\ControlSet001\Control\SafeBoot\Minimal\{4D36E967-E325-11CE-BFC1-08002BE10318}
    691 System\CurrentControlSet\Services\VxD\VNETSUP
    691 SYSTEM\ControlSet001\Control\SafeBoot\Network\{4D36E967-E325-11CE-BFC1-08002BE10318}
    687 System\
    683 SYSTEM\CurrentControlSet\Services\WinDHCPsvc
    656 SYSTEM\CurrentControlSet\Control
    618 System\CurrentControlSet\Control
    608 SYSTEM\CurrentControlSet\services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000001
    606 SYSTEM\CurrentControlSet\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries
    558 SYSTEM\CurrentControlSet
    556 SYSTEM\CurrentControlSet\Control\SafeBoot
    542 SYSTEM\CurrentControlSet\Services\srservice
    539 SYSTEM\CurrentControlSet\Services\Messenger
    517 SYSTEM\CurrentControlSet\Services\%s\Parameters
    496 System\CurrentControlSet\Control\ProductOptions
    481 SYSTEM\CurrentControlSet\Services\RemoteRegistry
    465 SYSTEM\CurrentControlSet\Services\WinSock2\speednet_sph
    462 SYSTEM\CurrentControlSet\Services\TlntSvr
    455 SYSTEM\CurrentControlSet\Services\RemoteAccess\RouterManagers\Ip
    452 SYSTEM\ControlSet001\Control\StorageDevicePolicies\WriteProtect
    437 System\CurrentControlSet\Services\RemoteAccess
    433 system\CurrentControlSet\Services\VxD\VNETSUP
    413 System\CurrentControlSet\Services\SharedAccess
    407 SYSTEM\CurrentControlSet\Services\CelInDrv
    404 System\CurrentControlSet\Control\ComputerName\ComputerName
    395 SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal
    393 SYSTEM\CurrentControlSet\Control\SafeBoot\Network
    382 SYSTEM\MountedDevices
    374 SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\
    372 SYSTEM\CurrentControlSet\Control\Nls\Language
    369 System\CurrentControlSet\Services\10DD75E0
    367 SYSTEM\CurrentControlSet\Control\Terminal Server\
    364 SYSTEM\CurrentControlSet\Services\wuauserv
    359 SYSTEM\ControlSet001\Services\srservice
    355 SYSTEM\CurrentControlSet\Services\navapsvc
    353 system\wininv.dll
    352 system\winkey.dll
    351 SYSTEM\ControlSet001\Services\navapsvc
    338 SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    337 SYSTEM\ControlSet002\Control\Terminal Server\
    318 SYSTEM\CurrentControlSet\Services\BITS\Parameters
    314 SYSTEM\CurrentControlSet\Control\Class\{4D36E96D-E325-11CE-BFC1-08002BE10318}\
    313 SYSTEM\CurrentControlSet\Services\10DD75E0
    312 SYSTEM\CurrentControlSet\Services\Winsock\Parameters
    310 SYSTEM\CurrentControlSet\Services\Winsock2\Parameters
    295 SYSTEM\CurrentControlSet\Control\SafeBoot\
    294 System\CurrentControlSet\Services\AE2CA9B0
    290 SYSTEM\InfoTime
    288 system\CurrentControlSet\Services
    284 SYSTEM\CurrentControlSet\Control\nls\codepage
    280 SYSTEM\ControlSet001\Services\kspooldaemon
    279 system\cURRENTcONTROLsET\sERVICES\%s
    278 System\CurrentControlSet\Services\VxD\MSTCP
    273 System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    272 SYSTEM\CurrentControlSet\Services\ERSvc
    271 System\CurrentControlSet\Control\MPRServices\TestService
    270 SYSTEM\ControlSet001\Enum\Root\LEGACY_KSPOOLDAEMON\0000
    266 SYSTEM\CurrentControlSet\Control\Session Manager\Environment
    262 SYSTEM\CurrentControlSet\Control\Windows
    261 System\CurrentControlSet\Control\Lsa
    254 System\CurrentControlSet\Services\KAVsys
    254 SYSTEM\ControlSet003\Services\BITS\Parameters
    252 SYSTEM\ControlSet001\Services\KSD2Service
    239 SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\
    238 SYSTEM\ControlSet001\Services\wscsvc
    232 SYSTEM\CurrentControlSet\Control\ComputerName\ComputerName
    230 SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
    225 System\CurrentControlSet\Services\Tcpip\Parameters
    223 SYSTEM\CurrentControlSet\Services\AeLookupSvcs
    214 system\cURRENTcONTROLsET\sERVICES\
    214 SYSTEM\CurrentControlSet\Services\Schedule
    210 SYSTEM\CurrentControlSet\Control\Class
    209 System\CurrentControlSet\Services
    207 SYSTEM\CurrentControlSet\Services\kkdc
    205 System\CurrentControlSet\Services\%s
    202 SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile\AuthorizedApplications\List
    198 SYSTEM\ControlSet001\Services\wuauserv
    194 SYSTEM\CurrentControlSet\Services\NetBT\Parameters
    192 SYSTEM\CurrentControlSet\Services\CSNetManagerXp
    189 SYSTEM\ControlSet001\Services\SharedAccess
    188 System\CurrentControlSet\Services\Class\
    185 SYSTEM\CurrentControlSet\Services\Class
    182 SYSTEM\CurrentControlSet\Services\W32Time\Parameters
    180 System\CurrentControlSet\Services\WinSock2\Parameters\
    180 System\CurrentControlSet\Services\E2C9CC2C
    176 SYSTEM\CurrentControlSet\Services\SSHNAS
    175 System\CurrentControlSet\Control\Class\
    175 SYSTEM\Setup
    175 SYSTEM\CurrentControlSet\Services\BITS
    174 SYSTEM\CurrentControlSet\Services\DomainService
    174 SYSTEM\CurrentControlSet\Control\SafeBoot\Network\
    173 SYSTEM\CurrentControlSet\Services\ManagereUpdate
    172 SYSTEM\CurrentControlSet\Services\WinSock2\ESPI11
    169 SYSTEM\CurrentControlSet\Services\acpidisk
    168 SYSTEM\CurrentControlSet\Services\Ball\
    167 SYSTEM\CurrentControlSet\Services\Medie Sariel Number Services
    166 SYSTEM\CurrentControlSet\Services\Kingsoft Antivirus WebShield Service
    164 System\WPA\ApplianceServer
    164 SYSTEM\CurrentControlSet\Services\Ball
    163 SYSTEM\CurrentControlSet\Control\TimeZoneInformation

Thanks to VirusShare (thanks!!!), I recently doubled my malware collection and once I got the samples, I ran the same stats as I did with 300K samples

The results are not very surprising, but for the benefit of all, here they are – top 100 strings and APIs:

71683194 ZYYd
 9614600 SVWU
 8510696 SVW3
 5945175 QSVW
 5146615 Self
 5097074 Left
 4901592 Width
 4866679 Height
 2661888 Y_^[
 2610729 Z]_^[
 2603363 TObject
 2500401 Sender
 2427775 SVWUQ
 2221590 SVWQ
 2098892 Integer
 2041679 SSSSS
 2004524 OnClick
 1959797 TabOrder
 1869961 ffffff
 1839874 ParentFont
 1799717 Z_^[
 1685639 Font.Style
 1685400 Font.Color
 1684559 Font.Name
 1679994 Font.Charset
 1677779 Font.Height
 1675337 TImage
 1533562 Caption
 1532251 SUVW
 1523722 VVVVV
 1330863 YZ^[
 1330718 YZ]_^[
 1289920 Boolean
 1272777 Cursor
 1245718 crHandPoint
 1176021 Controls
 1119964 kernel32.dll
 1067711 Classes
 1066917 TLabel
 1057670 BorderStyle
 1054490 Graphics
 1044623 YZ_^[
 1025276 clWindowText
 1012871 Color
  986327 ANSI_CHARSET
  982837 TEdit
  982375 QCCe
  971709 MaxLength
  967265 Forms
  958946 bsNone
  944070 GetProcAddress
  915245 WWWWW
  908645 GetModuleHandleA
  890753 AutoSize
  873797 OnChange
  835864 D$ P
  819162 fsBold
  798371 IGGc
  776076 LoadLibraryA
  773533 DEFAULT_CHARSET
  748235 Transparent
  735901 MS Sans Serif
  717404 CloseHandle
  698784 Y_^][
  685014 Visible
  680888 ExitProcess
  664088 GetModuleFileNameA
  652008 WriteFile
  640725 fffffffff
  638676 VirtualAlloc
  632279 user32.dll
  627775 MessageBoxA
  625640 Verdana
  625252 OnKeyPress
  621739 D$$P
  605312 RegCloseKey
  587883 CreateFileA
  585205 D$(P
  583562 Sleep
  580111 GetLastError
  575028 BBBB
  548097 FreeLibrary
  542390 VirtualFree
  540328 D$,P
  531015 SVWj
  527326 PPPPP
  526237 Create
  520984 IKKe
  512493 ReadFile
  512283 RegQueryValueExA
  503601 D$0P
  499179 Menus
  494051 SetFilePointer
  491272 GetCurrentThreadId
  486630 advapi32.dll
  485213 RegOpenKeyExA
  478247 FCCr
  477028 OHHi
  470003 L$ Q
  469449 Enabled
 
and APIs

944070    GetProcAddress
908645    GetModuleHandleA
776076    LoadLibraryA
717404    CloseHandle
680888    ExitProcess
664088    GetModuleFileNameA
652008    WriteFile
638676    VirtualAlloc
627775    MessageBoxA
605312    RegCloseKey
587883    CreateFileA
583562    Sleep
580111    GetLastError
548097    FreeLibrary
542390    VirtualFree
512493    ReadFile
512283    RegQueryValueExA
494051    SetFilePointer
491272    GetCurrentThreadId
485213    RegOpenKeyExA
463534    GetStdHandle
435175    EnterCriticalSection
433130    LeaveCriticalSection
431887    MultiByteToWideChar
428780    GetCommandLineA
426579    LocalAlloc
426383    GetTickCount
424661    DeleteCriticalSection
416464    InitializeCriticalSection
415052    GetStartupInfoA
403254    FindClose
399632    GetCurrentProcess
391872    GetFileSize
387944    GetLocaleInfoA
386549    WideCharToMultiByte
376113    FindFirstFileA
368695    CreateThread
355701    lstrlenA
349823    RtlUnwind
347012    WaitForSingleObject
333669    UnhandledExceptionFilter
329287    GetSystemMetrics
327685    DeleteFileA
324716    VirtualQuery
323620    GetVersion
322321    GetCurrentProcessId
321928    GetVersionExA
320611    SetEndOfFile
314143    RaiseException
313811    GetThreadLocale
312354    LocalFree
310272    TlsSetValue
308747    TlsGetValue
306651    CharNextA
306325    GetACP
295599    LoadStringA
290795    TerminateProcess
285458    GetCPInfo
275774    RegSetValueExA
275053    ShowWindow
273978    InterlockedDecrement
273819    GetDC
273356    InterlockedIncrement
268980    GetFileType
261534    DeleteObject
258627    SelectObject
257670    HeapAlloc
257553    GetActiveWindow
250951    CreateProcessA
249336    GlobalAlloc
244183    VirtualProtect
238796    SendMessageA
237408    GetDeviceCaps
235324    LoadLibraryExA
231840    GetLastActivePopup
228711    GlobalFree
228678    GetSystemDirectoryA
228410    DestroyWindow
227835    HeapFree
224168    GetTempPathA
223629    QueryPerformanceCounter
223618    DispatchMessageA
223499    wsprintfA
223381    SysFreeString
221520    LoadResource
219417    DeleteDC
218877    CreateWindowExA
214804    GetWindowRect
213161    lstrcpynA
212451    TranslateMessage
208053    ReleaseDC
207416    CompareStringA
204825    SetEvent
203100    RegCreateKeyExA
202788    SizeofResource
202324    GetClientRect
201382    GetLocalTime
200791    CreateEventA
200663    SetTextColor
200383    exit