TROJ_FAKESYS.GO

October 09, 2012
 Modified by: Mark Joseph Manahan
 ALIASES:

Trojan:Win32/FakeSysdef (Microsoft); FakeAlert-SysDef.ae (McAfee); Trojan.Win32.Fakesysdef.ae (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size:

342,528 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

17 Jun 2012

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops a copy of itself in the following folders using different file names:

  • %System Root%\DOCUMENTS AND SETTINGS\ALL USERS\APPLICATION DATA\WBPOPKGEWSA.EXE

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It adds the following possibly malicious files or file components:

  • %User Temp%\wuauclt.exe
  • %User Profile%\Recent\Desktop.ini
  • %System Root%\DOCUMENTS AND SETTINGS\ALL USERS\APPLICATION DATA\{random}X.EXE

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It executes then deletes itself afterward.

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WbpOPKGEWSa.exe = "%System Root%\Documents and Settings\All Users\Application Data\WbpOPKGEWSa.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
ActiveDesktop
HidNoChangingWallPaperden = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer
EnableAutoTray = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDesktop = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
TaskbarGlomLevel = "2"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowMyMusic = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowMyGames = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowSearch = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowRecentDocs = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowMyDocs = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowPrinters = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowNetPlaces = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowMyPics = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowSetProgramAccessAndDefaults = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowRun = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
TaskbarGlomming = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowUser = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowControlPanel = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowHelp = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowMyComputer = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Start_ShowNetConn = "0"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}sard.com/s.php?0Q9oBPXEN0uECUgzEJ95RQsajjrvq1aG3F/2q5sb+0bGiifT3WrzQQ==
  • http://{BLOCKED}ahote.com/?ylOdR9GQqXquMlTvsmXlkaz1x3Eb/w==
  • http://{BLOCKED}uinesc.com/s.php?0Q9oBPXEN0uECUgzEJ95RQsajjrvq1aG3F/2q5sb+0bGiifT3WrzQQ==
  • http://{BLOCKED}inca.com/?ylOdR9GQqXquMlTvsmXlkaz1x3Eb/w==
  • http://{BLOCKED}stgolfc.com/s.php?0Q9oBPXEN0uECUgzEJ95RQsajjrvq1aG3F/2q5sb+0bGiifT3WrzQQ==
  • http://{BLOCKED}elar.com/s.php?0Q9oBPXEN0uECUgzEJ95RQsajjrvq1aG3F/2q5sb+0bGiifT3WrzQQ==

NOTES:

It sets the attributes of all files in physical drives to Hidden.

It also moves all the files of the following folders:

  • %System Root%\Documents and Settings\All Users\Start Menu moved to %User Temp%\smtmp\1
  • %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch moved to %User Temp%\smtmp\2