ALIASES:

Worm:Win32/Gamarue.I (Microsoft); W32/Worm-FFE!F5F998A2425A (McAfee); Downloader.Dromedan (Symantec); Backdoor.Win32.Androm.a (Kaspersky); Troj/Gamarue-AG (Sophos); Trojan-Downloader.Win32.Dofoil.a (v) (Sunbelt); Trojan horse Defiler.G (AVG)

 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:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware 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: 13,824 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Jun 2014

Arrival Details

This spyware 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 spyware creates the following folders:

  • %User Temp%\5.tmp
  • %User Temp%\afolder
  • %User Temp%\ztmp
  • %User Profile%\Microsoft\sys32

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %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 spyware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Driver = "%Windows%\driver.exe"

Other System Modifications

This spyware deletes the following files:

  • %User Temp%\5.tmp
  • %User Temp%\5.tmp\7ZAEXE~1.GZ
  • %User Temp%\5.tmp\gzip.exe
  • %User Temp%\5.tmp\sys32.7z
  • %User Temp%\5.tmp\ZDRIVE~1.EXE
  • %Windows%\Web\bullet.gif
  • %Windows%\Web\deskmovr.htt
  • %Windows%\Web\exclam.gif
  • %Windows%\Web\safemode.htt
  • %Windows%\Web\tip.htm
  • %Windows%\Web\tips.gif

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\software\microsoft\
windows\currentversion\Policies\
Explorer\Run

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
4048 = "%User Temp%\mszyygpsi.exe"

Dropping Routine

This spyware drops the following files:

  • %User Temp%\mszyygpsi.exe
  • %User Temp%\00014244.exe
  • gzip.exe
  • sys32.7z
  • 7za.exe.gz
  • zdriver32.exe
  • %User Temp%\ztmp\t483.exe
  • 7za.exe
  • drive.exe
  • driver.exe
  • minerd.exe
  • libcurl-4.dll
  • pthreadGC2.dll
  • zlib1.dll
  • %User Temp%\ztmp\t22518.exe
  • %System%\gzip.exe
  • %System%\sys32.7z
  • %System%\7za.exe.gz
  • %Windows%\zdriver32.exe
  • %User Profile%\sys32\sys32.7z
  • %User Profile%\sys32\7za.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.. %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 spyware connects to the following possibly malicious URL:

  • {BLOCKED}.114.62
  • {BLOCKED}.131.39
  • {BLOCKED}.48.76
  • {BLOCKED}26.39

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.700

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 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_LOCAL_MACHINE\software\microsoft\windows\currentversion\Policies\Explorer
    • Run

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Driver = "%Windows%\driver.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • 4048 = "%User Temp%\mszyygpsi.exe"

Step 5

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%\mszyygpsi.exe
  • %User Temp%\00014244.exe
  • gzip.exe
  • sys32.7z
  • 7za.exe.gz
  • zdriver32.exe
  • %User Temp%\ztmp\t483.exe
  • 7za.exe
  • drive.exe
  • driver.exe
  • minerd.exe
  • libcurl-4.dll
  • pthreadGC2.dll
  • zlib1.dll
  • %User Temp%\ztmp\t22518.exe
  • %System%\gzip.exe
  • %System%\sys32.7z
  • %System%\7za.exe.gz
  • %Windows%\zdriver32.exe
  • %User Profile%\sys32\sys32.7z
  • %User Profile%\sys32\7za.exe

Step 6

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%\5.tmp
  • %User Temp%\afolder
  • %User Temp%\ztmp
  • %User Profile%\Microsoft\sys32

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_GAMARUE_BL132AB8.TOMC. 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 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Temp%\5.tmp
  • %User Temp%\5.tmp\7ZAEXE~1.GZ
  • %User Temp%\5.tmp\gzip.exe
  • %User Temp%\5.tmp\sys32.7z
  • %User Temp%\5.tmp\ZDRIVE~1.EXE
  • %Windows%\Web\bullet.gif
  • %Windows%\Web\deskmovr.htt
  • %Windows%\Web\exclam.gif
  • %Windows%\Web\safemode.htt
  • %Windows%\Web\tip.htm
  • %Windows%\Web\tips.gif


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