arrow_back
search
close

TROJ_SAMCA.B

April 12, 2016
 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:

503,296 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

12 Apr 2016

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 Temp%\MTemp1
  • %User Profile%\Application Data\MCommon1
  • %User Profile%\Application Data\WinLiveUpdate
  • %User Profile%\Application Data\Mozilla
  • %User Profile%\Mozilla\Firefox
  • %User Profile%\Firefox\Extensions
  • %User Profile%\Extensions\MozillaHotfix
  • %User Profile%\MozillaHotfix\chrome
  • %User Profile%\chrome\content
  • %User Profile%\chrome\skin

(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.. %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
WindowsLiveUpdate = "%User Temp%\WindowsLiveUp.exe startup"

It registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{1adefb8e-b913-32e6-86e2-3b7841f5d2a8}

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Approved Extensions

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
Firefox\Extensions

HKEY_CURRENT_USER\SOFTWARE\Mozilla\
Firefox\Extensions

HKEY_CLASSES_ROOT\IE.PerformancePack

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IE.PerformancePack\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\
4.7.3.5

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\ProgId

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\Implemented Categories

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\Implemented Categories\
{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Component Categories\{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Approved Extensions
{1ADEFB8E-B913-32e6-86E2-3B7841F5D2A8} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
Firefox\Extensions
hotfix@mozilla.org = "%User Profile%\Extensions\MozillaHotfix"

HKEY_CURRENT_USER\Software\Mozilla\
Firefox\Extensions
hotfix@mozilla.org = "%User Profile%\Extensions\MozillaHotfix"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
ThreadingModel = "Both"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
Class = "IE.PerformancePack"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
Assembly = "MSLive, Version=4.7.3.5, Culture=neutral, PublicKeyToken=null"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
RuntimeVersion = "v2.0.50727"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
CodeBase = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\
4.7.3.5
Class = "IE.PerformancePack"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\
4.7.3.5
Assembly = "MSLive, Version=4.7.3.5, Culture=neutral, PublicKeyToken=null"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\
4.7.3.5
RuntimeVersion = "v2.0.50727"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\
4.7.3.5
CodeBase = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Component Categories\{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}
0 = ".NET Category"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{1adefb8e-b913-32e6-86e2-3b7841f5d2a8}
NoExplorer = "1"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1A10 = "0"

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
{A8A88C49-5EB2-4990-A1A2-0876022C854F} = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
{AEBA21FA-782A-4A90-978D-B72164C80120} = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\MTool.exe
  • %User Temp%\MTool.exe.config
  • %User Temp%\temp.cmd
  • %User Profile%\MCommon1\sites.dat
  • %User Profile%\MCommon1\config.dat
  • %User Profile%\MCommon1\vinfo.dat
  • %User Profile%\MCommon1\uid1.dat
  • %User Profile%\WinLiveUpdate\MSLive.dll
  • %User Profile%\WinLiveUpdate\Interop.SHDocVw.dll
  • %User Profile%\WinLiveUpdate\MSHTMLSubset.dll
  • %User Profile%\WinLiveUpdate\ie9lib.dll
  • %User Profile%\MozillaHotfix\chrome.manifest
  • %User Profile%\MozillaHotfix\install.rdf
  • %User Profile%\content\addlist.js
  • %User Profile%\content\em.xul
  • %User Profile%\content\hashtable.js
  • %User Profile%\content\overlay.xul
  • %User Profile%\content\update.js
  • %User Temp%\WindowsLiveUp.exe.config
  • %User Temp%\WindowsLiveUp.exe

(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.. %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.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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

Close all opened browser windows

Step 4

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_CURRENT_USER\Software\Microsoft\Internet Explorer
    • Approved Extensions
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox
    • Extensions
  • In HKEY_CURRENT_USER\SOFTWARE\Mozilla\Firefox
    • Extensions
  • In HKEY_CLASSES_ROOT
    • IE.PerformancePack
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\IE.PerformancePack
    • CLSID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • {1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}
    • InprocServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
    • 4.7.3.5
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}
    • ProgId
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}
    • Implemented Categories
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\Implemented Categories
    • {62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Component Categories
    • {62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}

Step 5

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
    • WindowsLiveUpdate = "%User Temp%\WindowsLiveUp.exe startup"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Approved Extensions
    • {1ADEFB8E-B913-32e6-86E2-3B7841F5D2A8} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox\Extensions
    • hotfix@mozilla.org = "%User Profile%\Extensions\MozillaHotfix"
  • In HKEY_CURRENT_USER\Software\Mozilla\Firefox\Extensions
    • hotfix@mozilla.org = "%User Profile%\Extensions\MozillaHotfix"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
    • ThreadingModel = "Both"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
    • Class = "IE.PerformancePack"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
    • Assembly = "MSLive, Version=4.7.3.5, Culture=neutral, PublicKeyToken=null"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
    • RuntimeVersion = "v2.0.50727"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32
    • CodeBase = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\4.7.3.5
    • Class = "IE.PerformancePack"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\4.7.3.5
    • Assembly = "MSLive, Version=4.7.3.5, Culture=neutral, PublicKeyToken=null"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\4.7.3.5
    • RuntimeVersion = "v2.0.50727"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1ADEFB8E-B913-32E6-86E2-3B7841F5D2A8}\InprocServer32\4.7.3.5
    • CodeBase = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Component Categories\{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}
    • 0 = ".NET Category"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{1adefb8e-b913-32e6-86e2-3b7841f5d2a8}
    • NoExplorer = "1"

Step 6

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\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1A10 = "0"
      To: 1A10 = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: {A8A88C49-5EB2-4990-A1A2-0876022C854F} = "{random values}"
      To: {A8A88C49-5EB2-4990-A1A2-0876022C854F} = ""{random values}""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: {AEBA21FA-782A-4A90-978D-B72164C80120} = "{random values}"
      To: {AEBA21FA-782A-4A90-978D-B72164C80120} = ""{random values}""

Step 7

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%\MTool.exe
  • %User Temp%\MTool.exe.config
  • %User Temp%\temp.cmd
  • %User Profile%\MCommon1\sites.dat
  • %User Profile%\MCommon1\config.dat
  • %User Profile%\MCommon1\vinfo.dat
  • %User Profile%\MCommon1\uid1.dat
  • %User Profile%\WinLiveUpdate\MSLive.dll
  • %User Profile%\WinLiveUpdate\Interop.SHDocVw.dll
  • %User Profile%\WinLiveUpdate\MSHTMLSubset.dll
  • %User Profile%\WinLiveUpdate\ie9lib.dll
  • %User Profile%\MozillaHotfix\chrome.manifest
  • %User Profile%\MozillaHotfix\install.rdf
  • %User Profile%\content\addlist.js
  • %User Profile%\content\em.xul
  • %User Profile%\content\hashtable.js
  • %User Profile%\content\overlay.xul
  • %User Profile%\content\update.js
  • %User Temp%\WindowsLiveUp.exe.config
  • %User Temp%\WindowsLiveUp.exe

Step 8

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 Temp%\MTemp1
  • %User Profile%\Application Data\MCommon1
  • %User Profile%\Application Data\WinLiveUpdate
  • %User Profile%\Application Data\Mozilla
  • %User Profile%\Mozilla\Firefox
  • %User Profile%\Firefox\Extensions
  • %User Profile%\Extensions\MozillaHotfix
  • %User Profile%\MozillaHotfix\chrome
  • %User Profile%\chrome\content
  • %User Profile%\chrome\skin

Step 9

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


Did this description help? Tell us how we did.