Analysis by: Erika Bianca Mendoza
 Modified by: Karl Dominguez
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware.

It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 35,840 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 18 Jan 2011
Payload: Downloads files, Compromises system security, Modifies system registry

Arrival Details

This Trojan may be downloaded by other malware/grayware/spyware from remote sites.

It may be dropped by other malware.

Installation

This Trojan injects itself into the following processes running in the affected system's memory:

  • All processes except the following:
  • lsass.exe
  • services.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • sKf_hd4LBkJasd
  • aQs43kLKJ2ud3jaSD

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
CTF Products Updater = rundll32.exe {malware path and file name}, DepCmd

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = {malware path and file name}

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
LoadAppInit_DLLs = 1

(Note: The default value data of the said registry entry is 0.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Intel\
Common

Backdoor Routine

This Trojan opens the following ports:

  • 81

It connects to the following websites to send and receive information:

  • {BLOCKED}9.{BLOCKED}9.228.199
  • {BLOCKED}5.{BLOCKED}8.185.16

Download Routine

This Trojan saves the files it downloads using the following names:

  • %user temp%\slvc_25.tmp
  • %user temp%\sc.vbs

NOTES:
It targets the following Internet Browsers to monitor the activities of the user:

  • iexplore.exe
  • firefox.exe
  • chrome.exe
It intercept search strings in the following Web Sites:
  • Google
  • Bing
  • Yahoo
The gathered data is sent to the above-mentioned IP addresses. It can also download other possibly malicious files for these sites.

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.774.20
FIRST VSAPI PATTERN DATE: 18 Jan 2011
VSAPI OPR PATTERN File: 7.775.00
VSAPI OPR PATTERN Date: 18 Jan 2011

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Scan your computer with your Trend Micro product and note files detected as TROJ_DEEPEC.MS

Step 3

Restart in Safe Mode

[ Learn More ]

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\Intel
    • Common

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
    • CTF Products Updater = rundll32.exe {malware path and file name}, DepCmd

Step 6

Restore this modified 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 NT\CurrentVersion\Windows
    • AppInit_DLLs = {malware path and file name}
      • AppInit_DLLs = {blank}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
    • LoadAppInit_DLLs = 1
      • LoadAppInit_DLLs = 0

Step 7

Search and delete these files

[ Learn More ]
There may be some component 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%\slvc_25.tmp
  • %User Temp%\sc.vbs

Step 8

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