ALIASES:

Trojan:Win32/Wantvi.I (Microsoft); Generic Dropper.nu (McAfee); Trojan.Dropper (Symantec); Packed.Win32.Krap.t (Kaspersky); Packed.Win32.Krap.t (v) (Sunbelt); Trojan.Generic.2226749 (FSecure)

 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.

  TECHNICAL DETAILS

File Size: 47,104 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 23 Apr 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.

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
braviax = "é6"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
braviax = "é6"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1208 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
2500 = "3"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1208 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
2500 = "3"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1208 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
2500 = "3"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1208 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2500 = "3"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1208 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\
Security Center
AntiVirusDisableNotify = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Security Center
FirewallDisableNotify = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Security Center
UpdatesDisableNotify = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Enable Browser Extensions = "yes"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Search Bar = "http://www.{BLOCKED}e.com/ie"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1200 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1201 = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1608 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1804 = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1200 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1201 = "0"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1608 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1804 = "1"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1200 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1201 = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1608 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1804 = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1200 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1201 = "0"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1608 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1804 = "1"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1200 = "0"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1201 = "0"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1608 = "0"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1804 = "1"

(Note: The default value data of the said registry entry is 3.)

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

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

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

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Search Page = "http://www.{BLOCKED}e.com"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch.)

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}e.com"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Search_URL = "http://www.{BLOCKED}e.com/ie"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Search Page = "http://www.{BLOCKED}e.com"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}e.com"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Search
SearchAssistant = "http://www.{BLOCKED}e.com"

(Note: The default value data of the said registry entry is http://ie.search.msn.com/{SUB_RFC1766}/srchasst/srchasst.htm.)

Dropping Routine

This Trojan drops the following files:

  • %System%\dllcache\figaro.sys
  • %System%\braviax.exe
  • %Windows%\drivers\beep.sys
  • %System%\dllcache\beep.sys
  • %System%\drivers\beep.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}rfadosater.com/?wmid=1019&d=3&it=2&s=30
  • http://{BLOCKED}otravontiy.com/?wmid=1019&d=3&it=2&s=30
  • http://{BLOCKED}anostrase.com/?wmid=1019&d=3&it=2&s=30
  • http://{BLOCKED}strovanios.com/?wmid=1019&d=3&it=2&s=30
  • http://{BLOCKED}kosionas.com/?wmid=1019&d=3&it=2&s=30

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • braviax = "é6"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • braviax = "é6"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
    • 1208 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
    • 2500 = "3"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • 1208 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • 2500 = "3"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • 1208 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • 2500 = "3"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • 1208 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • 2500 = "3"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • 1208 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • 2500 = "3"
  • In HKEY_CURRENT_USER\Software\Microsoft\Security Center
    • AntiVirusDisableNotify = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Security Center
    • FirewallDisableNotify = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Security Center
    • UpdatesDisableNotify = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • EnableFirewall = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Enable Browser Extensions = "yes"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Search Bar = "http://www.{BLOCKED}e.com/ie"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
    • 1200 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
    • From: 1201 = "0"
      To: 1201 = ""1""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
    • 1608 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
    • 1804 = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • 1200 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • From: 1201 = "0"
      To: 1201 = ""3""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • 1608 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • From: 1804 = "1"
      To: 1804 = ""1""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • 1200 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • From: 1201 = "0"
      To: 1201 = ""1""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • 1608 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • 1804 = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • 1200 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1201 = "0"
      To: 1201 = ""3""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • 1608 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1804 = "1"
      To: 1804 = ""1""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1200 = "0"
      To: 1200 = ""3""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1201 = "0"
      To: 1201 = ""3""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1608 = "0"
      To: 1608 = ""3""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1804 = "1"
      To: 1804 = ""3""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusDisableNotify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallDisableNotify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • UpdatesDisableNotify = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From: Search Page = "http://www.{BLOCKED}e.com"
      To: Search Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch""
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://www.{BLOCKED}e.com"
      To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Default_Search_URL = "http://www.{BLOCKED}e.com/ie"
      To: Default_Search_URL = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Search Page = "http://www.{BLOCKED}e.com"
      To: Search Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://www.{BLOCKED}e.com"
      To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Search
    • From: SearchAssistant = "http://www.{BLOCKED}e.com"
      To: SearchAssistant = ""http://ie.search.msn.com/{SUB_RFC1766}/srchasst/srchasst.htm""

Step 5

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System%\dllcache\figaro.sys
  • %System%\braviax.exe
  • %Windows%\drivers\beep.sys
  • %System%\dllcache\beep.sys
  • %System%\drivers\beep.sys

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_FAKEALE.SME. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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