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TROJ_REVETON.MM

April 11, 2013
 Analysis by: Adrianne Chester Camat
 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet


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 connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

103,936 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

08 Apr 2013

Payload:

Displays graphics/image, Collects system information

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 and executes them:

  • %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.dat

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It drops and executes the following files:

  • %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.js
  • %System Root%\Documents and Settings\All Users\Application Data\rundll32.exe (Normal File)

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Autostart Technique

This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ctfmon.exe = "%System Root%\Documents and Settings\All Users\Application Data\rundll32.exe %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.dat, {Random}"

(Note: The default value data of the said registry entry is "%System%\ctfmon.exe".)

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\msconfig.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
2500 = "{Hex Values}"

Other Details

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

  • https://newage.e-personal.net

NOTES:

It gathers the following information for its ransomware routine:

  • Ip Address,Location and ISP
  • Malware Version and SubID
  • OS Version
  • System Default Language ID
  • System Metrics(Desktop Width and Height)

Using this information, it locks the screen (disabling taskmgr.EXE and explorer.EXE) and displays a ransomware threat spoofing Police Central e-Crime Unit. It downloads an encrypted file and save it to the infected system as:

  • %System Root%\Documents And Settings\All Users\Application Data\{reversed malware filename}.pad

This encrypted file contains a .DLL file when decrypted. The contents of the encrypted file may vary depending on the remote server.

The .DLL file contains a lock screen image may look like the following image:

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.844.04

FIRST VSAPI PATTERN DATE:

08 Apr 2013

VSAPI OPR PATTERN File:

9.845.00

VSAPI OPR PATTERN Date:

09 Apr 2013

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

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.
  • %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.dat
  • %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.js
  • %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.pad
  • %System Root%\Documents and Settings\All Users\Application Data\rundll32.exe

Step 4

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • From: ctfmon.exe = "%System Root%\Documents and Settings\All Users\Application Data\rundll32.exe %System Root%\Documents and Settings\All Users\Application Data\{Random Characters}.dat, {Random}"
      To: ctfmon.exe = "%System%\ctfmon.exe"

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_REVETON.MM. 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 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_REVETON.MM. 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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