TROJ_DROPPER.XPH

January 22, 2013
 ALIASES:

Backdoor:Win32/Poison.E (Microsoft); Generic Dropper!f2g (McAfee); Trojan-Dropper.Win32.Dapato.bxey (Kaspersky); Trojan.Win32.Generic!BT (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.

  TECHNICAL DETAILS

File Size:

265,830 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Dec 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 the following copies of itself into the affected system:

  • %User Profile%\Application Data\winlive.exe

(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.)

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
Win Live Messenger = "%User Profile%\Application Data\winlive.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
winlive = "%User Profile%\Application Data\winlive.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\The Silicon Realms Toolworks\
Armadillo

HKEY_CLASSES_ROOT\CLSID\{793B04B2-7D89-13D1-B2E4-0060975B8649}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{793B04B2-7D89-13D1-B2E4-0060975B8649}\Version

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\The Silicon Realms Toolworks\
Armadillo
{047B9EB5F0B2420DE} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{793B04B2-7D89-13D1-B2E4-0060975B8649}
0 = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\The Silicon Realms Toolworks\
Armadillo
{0B2420DE47B9EB5F} = "{random values}"

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\7312972A.TMP

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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 key

[ 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\The Silicon Realms Toolworks
    • Armadillo
  • In HKEY_CLASSES_ROOT\CLSID
    • {793B04B2-7D89-13D1-B2E4-0060975B8649}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{793B04B2-7D89-13D1-B2E4-0060975B8649}
    • Version

Step 4

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Win Live Messenger = "%User Profile%\Application Data\winlive.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • winlive = "%User Profile%\Application Data\winlive.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\The Silicon Realms Toolworks\Armadillo
    • {047B9EB5F0B2420DE} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{793B04B2-7D89-13D1-B2E4-0060975B8649}
    • 0 = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\The Silicon Realms Toolworks\Armadillo
    • {0B2420DE47B9EB5F} = "{random values}"

Step 5

Search and delete this file

[ Learn More ]
There may be some files 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%\7312972A.TMP

Step 6

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