TROJ_FAKEAV.OBF

November 01, 2013
 Analysis by: Jennifer Gumban
 ALIASES:

Rogue:Win32/Winwebsec (Microsoft), Trojan-FakeAV.Win32.SmartFortress2012.aiui (Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • 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.

  TECHNICAL DETAILS

File Size:

736,904 bytes

File Type:

EXE

Initial Samples Received Date:

28 Oct 2013

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 the following file(s)/component(s):

  • %All Users Profile%\Application Data\{Random Characters}\{Random Characters}.exe.manifest
  • %All Users Profile%\Application Data\{Random Characters}\{Random Characters}.ico
  • %All Users Profile%\Application Data\{Random Characters}\{Random Characters 1}.in
  • %All Users Profile%\Application Data\{Random Characters}\{Random Characters 1}.lg
  • %All Users Profile%\Application Data\{Random Characters}\{Random Characters 2}
  • %All Users Profile%\Application Data\{Random Characters}\serv.bat
  • %User Profile%\Desktop\Antivirus Security Pro support.url
  • %User Profile%\Start Menu\Programs\Antivirus Security Pro\Antivirus Security Pro support.url

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It drops the following copies of itself into the affected system:

  • %All Users Profile%\Application Data\{Random Characters}\{Random Characters}.exe

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

It creates the following folders:

  • %All Users Profile%\Application Data\{Random Characters}
  • %User Profile%\Start Menu\Programs\Antivirus Security Pro

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
AS2014 = "%All Users Profile%\Application Data\{Random Characters}\{Random Characters}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
AS2014 = "%All Users Profile%\Application Data\{Random Characters}\{Random Characters}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,,%All Users Profile%\Application Data\{Random Characters}\{Random Characters}.exe -sm,"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc

HKEY_CURRENT_USER\Control Panel\don't load

It adds the following registry entries:

HKEY_CURRENT_USER\Control Panel\don't load
wscui.cpl = "No"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
AntiVirusDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
AntiVirusOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
UpdatesDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableVirtualization = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SystemRestore
RPSessionInterval = "0"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.1.127/api/stats/debug/1/?ts=829d05a4c48fa48e1cd4d6bf5c059ca39319864e&token=sysdocx1&group=asp&nid=8A000000&lid=0061&ver=0061&affid=46200
  • http://{BLOCKED}.1.127/api/dom/no_respond/?ts=829d05a4c48fa48e1cd4d6bf5c059ca39319864e&token=sysdocx1&group=asp&nid=8A000000&lid=0061&ver=0061&affid=46200&dx=0
  • http://{BLOCKED}.1.127/api/stats/debug/2/?ts=829d05a4c48fa48e1cd4d6bf5c059ca39319864e&token=sysdocx1&group=asp&nid=8A000000&lid=0061&ver=0061&affid=46200
  • http://{BLOCKED}.1.127/api/stats/debug/3/?ts=829d05a4c48fa48e1cd4d6bf5c059ca39319864e&token=sysdocx1&group=asp&nid=8A000000&lid=0061&ver=0061&affid=46200

NOTES:
It drops the following shortcut pointing to its copy:

  • %User Profile%\Desktop\Antivirus Security Pro.lnk
  • %User Profile%\Start Menu\Programs\Antivirus Security Pro\Antivirus Security Pro.lnk