Analysis by: Rika Joi Gregorio
ALIASES:

Worm:Win32/Gamarue.I(Microsoft), W32/Gamarue.worm(McAfee), W32/Androm.BMGM!tr.bdr(Fortinet), Win32/TrojanDownloader.Wauchos.X trojan(Eset)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It listens on port(s).

  TECHNICAL DETAILS

File Size: 98,304 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 Jan 2014

Arrival Details

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

  • %ProgramData%\explorer.exe (Windows Vista and 7 only)
  • %All Users Profile%\explorer.exe
  • %All Users Profile%\{random}.exe

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Start WingMan Profiler = "%All Users Profile%\explorer.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
540 = "%All Users Profile%\{random}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Start WingMan Profiler = "%ProgramData%\explorer.exe" (Windows Vista and 7 only and if Java update is disabled in startup)

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\WinRAR
HWID = "{random value}"

It creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:Enabled:{malware file name}"

Backdoor Routine

This backdoor listens on the following port(s):

  • 3232

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}codes.ru/new2/gate.php
  • http://{BLOCKED}versen.ru/new2/gate.php
  • http://{BLOCKED}y.su/new2/gate.php
  • http://{BLOCKED}sdietz.ru/new2/gate.php
  • http://{BLOCKED}king.ru/new2/gate.php
  • http://{BLOCKED}spetscompany.co.uk/p2.mod

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.574.04
FIRST VSAPI PATTERN DATE: 30 Jan 2014
VSAPI OPR PATTERN File: 10.575.00
VSAPI OPR PATTERN Date: 31 Jan 2014

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 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\CurrentVersion\Run
    • Start WingMan Profiler = "%All Users Profile%\explorer.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • 540 = "%All Users Profile%\{random}.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Start WingMan Profiler = "%ProgramData%\explorer.exe" (Windows Vista and 7 only and if Java update is disabled in startup)
  • In HKEY_CURRENT_USER\Software\WinRAR
    • HWID = "{random value}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware path and file name} = "{malware path and file name}:*:Enabled:{malware file name}"

Step 4

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