Analysis by: Mark Joseph Manahan
ALIASES:

Trojan:Win32/Claretore (Microsoft)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This spyware may be dropped by other malware.

It executes then deletes itself afterward.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 122,841 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 01 Aug 2012
Payload: Connects to URLs/IPs

Arrival Details

This spyware may be dropped by the following malware:

  • BKDR_SIMDA.RU

Installation

This spyware drops the following copies of itself into the affected system:

  • %User Profile%\{random}-0.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It executes then deletes itself afterward.

It injects codes into the following process(es):

  • winlogon.exe
  • wuauclt.exe
  • rundll32.exe
  • cmd.exe
  • far.exe
  • totalcmd.exe
  • chrome.exe
  • opera.exe
  • firefox.exe
  • iexplore.exe
  • explorer.exe

Autostart Technique

This spyware creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Update Server = "%User Profile%\{random}-0.exe"

Information Theft

This spyware gathers the following data:

  • Machine GUID
  • User name
  • Computer name
  • Windows install date
  • Disk identifier

Other Details

This spyware connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.15.125/chrome/report.html

NOTES:

This spyware checks for accessed websites that contains google-analytics.com/ga.js and replaces it with {BLOCKED}prock3.com/ga.js.

It hooks the following network APIs to intercept packets:

  • mswsock.dll.WSPStartup
  • ws2_32.dll.WSAStartup
  • ws2_32.dll.WSASocketA

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.320.02
FIRST VSAPI PATTERN DATE: 13 Aug 2012

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

Remove the malware/grayware file that dropped/downloaded TSPY_SIMDA.RUS

Step 3

Restart in Safe Mode

[ Learn More ]

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
    • Windows Update Server = "%User Profile%\{random}-0.exe"

Step 5

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