ALIASES:

Rogue:Win32/FakeScanti (Microsoft); FakeAlert-GA.gen.r (McAfee); HEUR:Trojan.Win32.Generic (Kaspersky); Troj/Sirefef-T (Sophos); LooksLike.Win32.Sirefef.h (v) (Sunbelt); Win32/Cryptor (AVG)

 PLATFORM:

Windows

 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 deletes itself after execution.

  TECHNICAL DETAILS

File Size: 2,800,640 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Dec 2014

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 creates the following folders:

  • %User Profile%\Application Data\RvS2ibF3pGaJdK
  • %User Profile%\Application Data\olBryonF4m5W7E
  • %User Profile%\Application Data\fZqhYCwkIrOtAuS
  • %Start Menu%\Programs\Cloud AV 2012
  • %User Profile%\CryptnetUrlCache\MetaData
  • %User Profile%\Microsoft\CryptnetUrlCache
  • %User Profile%\CryptnetUrlCache\Content

(Note: %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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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
TP0cS1ivDoGaHsK8234A = "%System%\Cloud AV 2012v121.exe"

Other System Modifications

This Trojan modifies the following file(s):

  • %System%\drivers\etc\hosts
  • %Application Data%\GDIPFONTCACHEV1.DAT

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It deletes the following folders:

  • %User Profile%\My Documents\My Pictures
  • %Start Menu%\Programs\Administrative Tools

(Note: %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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"

(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\dhl1.tmp
  • %User Temp%\dhl4.tmp
  • %User Temp%\dhl7.tmp
  • %User Temp%\dhlA.tmp
  • %User Temp%\dhlD.tmp
  • %User Temp%\dhl10.tmp
  • %User Temp%\fbi13.tmp
  • %User Temp%\dhl16.tmp
  • %User Temp%\dhl19.tmp
  • %User Temp%\dhl1C.tmp
  • %User Temp%\dhl1F.tmp
  • %System%\Cloud AV 2012v121.exe
  • %User Temp%\dhl24.tmp
  • %User Temp%\dhl27.tmp
  • %User Temp%\dhl2A.tmp
  • %User Temp%\dhl2D.tmp
  • %User Temp%\dhl30.tmp
  • %User Temp%\dhl33.tmp
  • %User Temp%\fbi36.tmp
  • %User Temp%\dhl39.tmp
  • %User Temp%\dhl3C.tmp
  • %User Temp%\dhl3F.tmp
  • %User Temp%\dhl42.tmp
  • %User Profile%\fZqhYCwkIrOtAuS\Cloud AV 2012.ico
  • %Start Menu%\Programs\Cloud AV 2012\Cloud AV 2012.lnk
  • %Desktop%\Cloud AV 2012.lnk
  • %User Profile%\MetaData\7B2238AACCEDC3F1FFE8E7EB5F575EC9
  • %User Profile%\Content\7B2238AACCEDC3F1FFE8E7EB5F575EC9
  • %User Profile%\MetaData\A44F4E7CB3133FF765C39A53AD8FCFDD
  • %User Profile%\Content\A44F4E7CB3133FF765C39A53AD8FCFDD
  • %User Profile%\MetaData\60E31627FDA0A46932B0E5948949F2A5
  • %User Profile%\Content\60E31627FDA0A46932B0E5948949F2A5
  • %User Profile%\MetaData\0797C381B2F87EB5A1D5573BD15BA4F4
  • %User Profile%\Content\0797C381B2F87EB5A1D5573BD15BA4F4
  • %User Profile%\MetaData\2BF68F4714092295550497DD56F57004
  • %User Profile%\Content\2BF68F4714092295550497DD56F57004
  • %User Profile%\MetaData\94308059B57B3142E455B38A6EB92015
  • %User Profile%\Content\94308059B57B3142E455B38A6EB92015
  • %Temp%\Cab76.tmp
  • %Temp%\Tar78.tmp

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.228.8
  • {BLOCKED}.228.0
  • {BLOCKED}202.59
  • {BLOCKED}4.122.156
  • {BLOCKED}0.1
  • {BLOCKED}5.190.8
  • {BLOCKED}85.163
  • {BLOCKED}61.169

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.700

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
    • TP0cS1ivDoGaHsK8234A = "%System%\Cloud AV 2012v121.exe"

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_CURRENT_USER\Software\Microsoft\GDIPlus
    • From: FontCachePath = "%Application Data%"
      To: FontCachePath = ""%User Profile%\Local Settings\Application Data""

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.
  • %User Temp%\dhl1.tmp
  • %User Temp%\dhl4.tmp
  • %User Temp%\dhl7.tmp
  • %User Temp%\dhlA.tmp
  • %User Temp%\dhlD.tmp
  • %User Temp%\dhl10.tmp
  • %User Temp%\fbi13.tmp
  • %User Temp%\dhl16.tmp
  • %User Temp%\dhl19.tmp
  • %User Temp%\dhl1C.tmp
  • %User Temp%\dhl1F.tmp
  • %System%\Cloud AV 2012v121.exe
  • %User Temp%\dhl24.tmp
  • %User Temp%\dhl27.tmp
  • %User Temp%\dhl2A.tmp
  • %User Temp%\dhl2D.tmp
  • %User Temp%\dhl30.tmp
  • %User Temp%\dhl33.tmp
  • %User Temp%\fbi36.tmp
  • %User Temp%\dhl39.tmp
  • %User Temp%\dhl3C.tmp
  • %User Temp%\dhl3F.tmp
  • %User Temp%\dhl42.tmp
  • %User Profile%\fZqhYCwkIrOtAuS\Cloud AV 2012.ico
  • %Start Menu%\Programs\Cloud AV 2012\Cloud AV 2012.lnk
  • %Desktop%\Cloud AV 2012.lnk
  • %User Profile%\MetaData\7B2238AACCEDC3F1FFE8E7EB5F575EC9
  • %User Profile%\Content\7B2238AACCEDC3F1FFE8E7EB5F575EC9
  • %User Profile%\MetaData\A44F4E7CB3133FF765C39A53AD8FCFDD
  • %User Profile%\Content\A44F4E7CB3133FF765C39A53AD8FCFDD
  • %User Profile%\MetaData\60E31627FDA0A46932B0E5948949F2A5
  • %User Profile%\Content\60E31627FDA0A46932B0E5948949F2A5
  • %User Profile%\MetaData\0797C381B2F87EB5A1D5573BD15BA4F4
  • %User Profile%\Content\0797C381B2F87EB5A1D5573BD15BA4F4
  • %User Profile%\MetaData\2BF68F4714092295550497DD56F57004
  • %User Profile%\Content\2BF68F4714092295550497DD56F57004
  • %User Profile%\MetaData\94308059B57B3142E455B38A6EB92015
  • %User Profile%\Content\94308059B57B3142E455B38A6EB92015
  • %Temp%\Cab76.tmp
  • %Temp%\Tar78.tmp

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Application Data\RvS2ibF3pGaJdK
  • %User Profile%\Application Data\olBryonF4m5W7E
  • %User Profile%\Application Data\fZqhYCwkIrOtAuS
  • %Start Menu%\Programs\Cloud AV 2012
  • %User Profile%\CryptnetUrlCache\MetaData
  • %User Profile%\Microsoft\CryptnetUrlCache
  • %User Profile%\CryptnetUrlCache\Content

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SIREFEF.GL. 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.

Step 8

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %System%\drivers\etc\hosts
    • %Application Data%\GDIPFONTCACHEV1.DAT


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